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  • Biochemistry  (177)
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  • 1993  (287)
  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 31 (1993), S. 1713-1723 
    ISSN: 0887-6266
    Keywords: phthalocyanine siloxane ; crystal structure ; epitaxial growth ; high-resolution electron microscopy ; molecular imaging ; polymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thin films of SiPc(OH)2 (Pc = phthalocyanine) were formed epitaxially on the (001) surface of mica by vacuum deposition and were then polymerized by heat treatment. The molecular packing of the SiPc(OH)2 was determined by electron diffraction and high-resolution electron microscopy as triclinic\documentclass{article}\pagestyle{empty}\begin{document}${\rm P\bar 1} $\end{document} having dimensions a = 0.727, b = 1.307, c = 0.688 nm, α = 102.5, β = 104.2, and γ = 97.4°. This monomer crystal grows with its c-axis parallel to the a-axis of the substrate mica and its bc-plane parallel to the (001) surface of mica. By heat treatment at 320°C, the SiPc(OH)2 polymerized with the c-axis of the polymer parallel to the c-axis of the monomer. At 420°C, the c-axis of the polymer became parallel to the a*-axis of the monomer (i.e., perpendicular to the film surface). From high-resolution electron microscopy of partially polymerized specimens, the polymerization was shown to start at the edges of small monomer crystals. This may be considered to be due to the volume expansion during the polymerization. © 1993 John Wiley & Sons, Inc.
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 31 (1993), S. 1923-1940 
    ISSN: 0887-6266
    Keywords: poly(4,4′-oxybibenzoate) ; polymerization ; morphology ; transitions ; crystal structure ; disclination domains ; Iamellae ; single crystals ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 4-Acetoxy 4′-carboxy biphenyl has been polymerized from solution, the bulk melt, and in constrained thin films, all below the melting point of the monomer as measured by differential scanning calorimetry (DSC). An isothermal sublimation-recrystallization-melting (and chemical change)-polymerization-crystallization process is proposed. From solution and in the thin films, single crystals consisting of ca. 100 Å thick lamellae are observed, with evidence for monomer addition-reaction on the end (top and bottom) surfaces. The bulk samples are fibrous, the “fibers” consisting of whisker-like single crystals. The polymer is highly heat and radiation (electron beam) resistant, with numerous successive electron diffraction (ED) patterns from the same crystal or sheared sample permitting comparison of the changes in ED patterns with transitions seen by DSC at ca. 350, 530, and 590°C. Phase I (a = 7.8, b = 5.5, c = 10.8 Å), a possible phase II (a = 15.6, b = 3.6 Å c = unknown), and a phase III (a = 9.0, b = 5.2 = √3a, c = 10.8 Å). Phases I and II are seen in samples polymerized at temperatures at and below 310°C; phase III is observed in samples polymerized at and above 350°C and in sheared samples. © 1993 John Wiley & Sons, Inc.
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  • 3
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 31 (1993), S. 1759-1767 
    ISSN: 0887-6266
    Keywords: rigid rod polymer ; thermotropic ; aromatic polyester ; fiber ; modulus ; crystal structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Fiber spinning and mechanical properties of four rigid polyesters with alkoxy substituents of different length and placement were evaluated. Properties of oriented fibers from the polymer with dodecyloxy substituents on the terephthalate moiety, PTA12HQ, were significantly affected by the crystal modification. At room temperature the following properties (tensile modulus E, tensile strength σb, and strain at break εb) could be obtained: E = 9.5 GPa, σb = 85 MPa and εb = 1.1% for phase Lf (the “frozen in layered mesophase”); E = 10.4 GPa, σb = 59 MPa and εb = 0.6% for modification A; E = 17.3 GPa, σb = 158 MPa and εb = 1.2% for modification B. Because of the higher amount of main chains per cross sectional area the polymer with hexyloxy side chains, PTA6HQ, showed better properties at a comparable degree of molecular orientation: E = 24 GPa, σb = 270 MPa, εb = 1.4%. Fibers obtained from the polyester with dodecyloxy substituents on the hydroquinone moiety, PTAHQ12, were too brittle to handle. The polyester with dodecyloxy substituents on both moieties, PTA12HQ12, was spun from the isotropic melt. Because of the obtained low degree of orientation, properties (E = 1 GPa, σb = 40 MPa, and εb = 6.3%) were governed by interactions between the chains (the main chains are not load-bearing). © 1993 John Wiley & Sons, Inc.
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  • 4
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993) 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
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  • 5
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 237-245 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The affinity of a ligand for a receptor is usually expressed in terms of the dissociation constant (Ki) of the drug-receptor complex, conveniently measured by the inhibition of radioligand binding. However, a ligand can be an antagonist, a partial agonist, or a full agonist, a property largely independent of its receptor affinity. This property can be quantitated as intrinsic activity (1A), which can range from 0 for a full antagonist to 1 for a full agonist. Although quantitative structure-activity relationship (QSAR) methods have been applied to the prediction of receptor affinity with considerable success, the prediction of IA, even qualitatively, has rarely been attempted. Because most traditional QSAR methods are limited to congeneric series, and there are often major structural differences between agonists and antagonists, this lack of success in predicting IA is understandable. To overcome this limitation, we used the method of comparative molecular field analysis (CoMFA), which, unlike traditional Hansch analysis, permits the inclusion of structurally dissimilar compounds in a single QSAR model. A structurally diverse set of 5-hydroxytryptamine1A (5-HT1A) receptor ligands, with literature IA data (determined by the inhibition of 5-HT sensitive forskolin-stimulated adenylate cyclase), was used to develop a 3-D QSAR model correlating intrinsic activity with molecular structure properties of 5HT1A receptor ligands. This CoMFA model had a crossvalidated r2 of 0.481, five components and final conventional r2 of 0.943. The receptor model suggests that agonist and antagonist ligands can share parts of a common binding site on the receptor, with a primary agonist binding region that is also occupied by antagonists and a secondary binding site accommodating the excess bulk present in the sidechains of many antagonists and partial agonists. The CoMFA steric field graph clearly shows that agonists tend to be “flatter” (more coplanar) than antagonists, consistent with the difference between the 5-HT1A agonist and antagonist pharmacophores proposed by Hibert and coworkers. The CoMFA electrostatic field graph suggests that, in the region surrounding the essential protonated aliphatic amino group, the positive molecular electrostatic potential may be weaker in antagonists as compared to agonists. Together, the steric and electrostatic maps suggest that in the secondary binding site region increased hydrophobic binding may enhance antagonist activity. These results demonstrate that CoMFA is capable of generating a statistically crossvalidated 3-D QSAR model that can successfully distinguish between agonist and antagonist 5-HT1A ligands. To the best of our knowledge, this is the first time this or any other QSAR method has been successfully applied to the correlation of structure with IA rather than potency or affinity. The analysis has suggested various structural features associated with agonist and antagonist behaviors of 5-HT1A ligands and thus should assist in the future design of drugs that act via 5-HT1A receptors. © 1993 John Wiley & Sons, Inc.
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  • 6
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 30-36 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We consider the tree search problem for the recurrence relation that appears in the evaluation of molecular integrals over Cartesian Gaussian basis functions. A systematic way of performing tree search is shown. By applying the result of tree searching to the LRL2 method of Lindh, Ryu, and Liu (LRL) (J. Chem. Phys., 95, 5889 1991), which is an auxiliary function-based method, we obtain significant reductions of the floating point operations (FLOPS) counts in the K4 region. The resulting FLOPS counts in the K4 region are comparable up to [dd|dd] angular momentum cases to the LRL1 method of LRL, currently the method requiring least FLOPS for [dd|dd] and higher angular momentum basis functions. For [ff|ff], [gg|gg], [hh|hh], and [ii|ii] cases, the required FLOPS are 24, 40, 51, and 59%, respectively, less than the LRL1 method in the K4 region. These are the best FLOPS counts available in the literature for high angular momentum cases. Also, there will be no overhead in either the K2 or K0 region in implementing the present scheme. This should lead to more efficient codes of integral evaluations for higher angular momentum cases than any other existing codes. © 1993 John Wiley & Sons, Inc.
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  • 7
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 19-29 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A method is proposed to perform computer simulations of protein dynamics in the long-time regime. The method is based upon a Monte Carlo technique. The only molecular degrees of freedom considered are bond rotations. All other degrees of freedom including the amide plane torsions are kept rigid. These constraints approximately account for all interactions related to chemical bonding. An individual Monte Carlo step adopts the Go and Scheraga algorithm where local conformational changes in a small window of the protein backbone are performed. By using correlated rotations, the conformation of residues outside the window remains invariant. To test the reliability of the method, the nonbonded interactions are turned off in the present application. Exact statistical averages are compared with values obtained from data of computer simulation involving 2 × 106 scans of the window along the protein backbone. Time is related to the number of scans of the window along the protein backbone. End-to-end distance autocorrelation functions decay to 1/e of its initial value in about 103-104 scans of the window algorithm. Time decay follows a stretched exponential Kohlrausch decay law. © 1993 John Wiley & Sons, Inc.
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  • 8
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 45-53 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The antitumor drug cis-diamminedichloroplatinum(II) (cisplatin) binds preferentially to GpG and ApG sequences of DNA, forming N7,N7 intrastrand chelates. Molecular modeling of the intrastrand adducts have been handicapped, so far, by the lack of force-field data describing the Pt-guanine and Pt-adenine binding. We used ab initio calculations with relativistic pseudopotentials to evaluate three important parameters for the platinum-adenine model complex [Pt(NH3)3(Ade)]2+: (1) the force constant for the Pt—N7 bond bending out of the adenine plane; (2) the energy profile for the torsion about Pt—N7; (3) a set of fractional atomic charges that reproduce the ab initio potential for a number of space points placed around the adduct. A population analysis and comparative study on the tetrammine complex [Pt(NH3)4]2+ have shown that for platinum adenine is a better σ-donor than NH3, but its capacity as a π-acceptor is weak. © 1993 John Wiley & Sons, Inc.
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  • 9
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 422-437 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A procedure is reported for the prediction of dense crystal structures of C-, H-, N-, O-, and F-containing organic compounds in the primitive triclinic, monoclinic, and orthorhombic space groups with Z ≤ 4. The crystal environments of molecules in 242 crystal structures have been analyzed to determine the common coordination sphere pattens. This led to the development of the MOLPAK (MOLecular PAcKing) program, which uses a rigid-body molecular structure probe to build packing arrangements (possible crystal structures) in the various space groups. A MOLPAK search, which involves the investigation of all unique orientations of a central molecule and the construction of the appropriate coordination patterns about the central molecule, provides a 3-D map of minimum unit cell volume as a function of the orientation of the central molecule. MOLPAK uses a repulsion-only potential and a preset threshold to place molecules in contact with each other. The 5-10 smallest volume packing arrangements from a search are subjected to a lattice energy minimization refinement with the WMIN program to yield possible crystal structures. The results are described from the analyses of several known compounds starting with the crystal molecular structures as the MOLPAK search probes in the P1, P21, P21/c, and P212121 space groups. In addition, several examples are given in which the search probes were created by AM1 geometry optimization of preliminary molecular models. More extensive data are given in supplementary tables. © 1993 John Wiley & Sons, Inc.
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  • 10
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 312-329 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A fully functional parallel version of the molecular dynamics (MD) module of AMBER3a has been implemented. Procedures parallelized include the calculation of the long-range nonbonded Coulomb and Lennard-Jones interactions, generation of the pairlist, intramolecular bond, angle, dihedral, 1-4 nonbonded interaction terms, coordinate restraints, and the SHAKE bond constraint algorithm. As far as we can determine, this is the first published description where a distributed-memory MIMD parallel implementation of the SHAKE algorithm has been designed to treat not only hydrogen-containing bonds but also all heavy-atom bonds, and where “shaken” crosslinks are supported as well. We discuss the subtasking and partitioning of an MD time-step, load balancing the nonbonded evaluations, describe in algorithmic detail how parallelization of SHAKE was accomplished, and present speedup, efficiency, and benchmarking results achieved when this hypercube adaptation of the MD module AMBER was applied to several variant molecular systems. Results are presented for speedup and efficiency obtained on the nCUBE machine, using up to 128 processors, as well as benchmarks for performance comparisons with the CRAY YMP and FPS522 vector machines. © 1993 John Wiley & Sons, Inc.
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  • 11
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993), S. 349-352 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We report the development of a new approximate method of calculating molecular surface areas. Our technique is based upon the method of Sharake and Rupley but incorporates several major advances. First, we represent the state of surface points as bits in a bit string so we can utilize Boolean operations to simultaneously turn off multiple test points in one Boolean AND operation. Second, we use a series of Boolean mask look-up tables to reduce the time complexity of the calculation of molecular surface area down to the same magnitude as doing a potential energy evaluation. When we use a 256 surface point sphere for all of the atoms in BPTI, a 454 nonhydrogen atom protein, and a 1.4-Å solvent probe, we in general underestimate the total solvent-accessible surface area (SASA) by approximately 1.25% with a correlation coefficient of 0.9990 over a wide range of conformations. The average CPU time required to calculate the SASA of a BPTI conformer is 0.58 s on an SGI 4D/220 workstation. We also describe a method by which we can calculate an approximate finite difference SASA gradient for BPTI in 0.79 of CPU time. © 1993 John Wiley & Sons, Inc.
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  • 12
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    Journal of Computational Chemistry 14 (1993), S. 378-378 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
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  • 13
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    Journal of Computational Chemistry 14 (1993), S. 728-735 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A method is proposed for calculating the forces in path integral theory and tested on semiclassic systems. It takes the range of the classic and quantum interactions into account and uses a second table within the neighbors table for the nearest neighbors. This method is found to be much more efficient than either the standard direct method or the traditional neighbors table, the efficiency increasing with the size of the system. The method can also be applied to clusters whose interaction centers are much farther apart than the distances between two consecutive members of the cluster. © 1993 John Wiley & Sons, Inc.
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  • 14
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    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 14 (1993) 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
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  • 15
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    Journal of Computational Chemistry 14 (1993), S. 445-451 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Parallelization of the SCF method for closed-shell molecules on the highly parallel transputer-based system PARAM is described. The parallelization has been implemented on three different hardware and software environments: (1) a network of bare 64 transputers; (2) configuration 1 plus a back-end file system (BFS); and (3) configuration 2 with one INTEL i860 processor. The evaluation of electron repulsion integrals (ERIs) and setting up of the Fock matrix is carried out in parallel on 64 nodes using minimal communication strategies. A good load balance is achieved for ERI evaluation with the help of bounds, local symmetry features, and the shell concept, as well as a data randomization technique, resulting into almost linear speedup (for ERI evaluation). In configurations 2 and 3, BFS is used for parallel storage and retrieval of ERIs. Further, in 3 matrix operations are implemented as remote procedure calls on the i860 processor. Routine techniques of level shifting and extrapolation are used for accelerating SCF convergence. The resulting package, INDMOL, has been tested for some randomly selected molecules having up to 255 contractions. Using configuration 3, a factor of 2 to 5 in computation time is obtained over 1, for the systems for which the ERIs cannot be stored in the distributed core memory. In summary, a heterogeneous system, as in configuration 3, can indeed be optimally exploited for programming peculiar diverse requirements of the SCF procedure. © 1993 John Wiley & Sons, Inc.
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  • 16
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    Journal of Computational Chemistry 14 (1993), S. 471-477 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: One of the features of the polypeptide backbone is that it represents a flexible chain that contains almost rigid CO—NH peptide bonds. One may try to substitute one or more such bonds by another relatively rigid unit to maintain the overall conformational properties of the backbone and at the same time modify some other properties of the molecule (“pseudopeptide”), such as the ability to form hydrogen bonds. By a detailed conformational analysis, it is shown that the carbon—carbon double bond is quite isosteric with the peptide bond and for this reason suitable for such a substitution. This is accomplished by applying molecular mechanics in calculation of the φ, ψ maps for pseudopeptide analogs of the N-acetyl-Ala-NHMe molecule. © 1993 John Wiley & Sons, Inc.
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  • 17
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    Journal of Computational Chemistry 14 (1993), S. 510-521 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We present analytical expressions to calculate the gradient of the water-accessible surface area of proteins with respect to Cartesian coordinates and dihedral angles. A detailed mathematical analysis leads to corrected equations for the gradient calculation used previously in the ANAREA program. To study the hydrophobic effect of solvent-protein interactions, our expressions have been implemented to further improve the program package FANTOM. We used this version of FANTOM to minimize the ECEPP/2 and the hydrophobic energy of tendamistat. © 1993 John Wiley & Sons, Inc.
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  • 18
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    Journal of Computational Chemistry 14 (1993), S. 530-540 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The electrostatic potentials of 21 molecules containing different functional groups has been computed at the ab initio RHF/6-31G* level on a series of solvent accessible surfaces and compared with MNDO, AM1, and PM3-derived pontentials. We analyzed in detail the distribution of electrostatic potentials on the surfaces around their maximum and minimum values and found out that consistently MNDO gives results similar to ab initio potentials. The actual values of the MNDO electrostatic potentials show a systematic deviation from the “correct” results, but the pattern of the MEP distribution on the surface is similar to that of the ab initio results. In contrast, PM3 fails in some cases to give even the correct number or distribution of “hot spots” of potential (low MEP) on the surface. AM1 behaves somewhere between these two semiempirical methods. As a conclusion, MNDO would be suggested as the best approach to analyses requiring a fast and efficient mapping of electrostatic potentials on simplified models of molecular surfaces. © 1993 John Wiley & Sons, Inc.
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  • 19
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    Journal of Computational Chemistry 14 (1993), S. 556-565 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We describe, test, and apply a new computational algorithm for generating protein loop conformations subject to distance and secondary structure constraints. The algorithm is based upon initial scaling and subsequent relaxation of covalent bond lengths. The scaling-relaxation procedure needs no additional energy terms and can be readily incorporated into existing molecular modeling packages. The algorithm uses an all-atom energy function from the outset in a straightforward way so that about 60% of the generated loop conformations are free of severe distortions of covalent bond lengths and angles. An extensive application to the major loop conformations of TFIIIA-type zinc fingers (Zif268 and ADR1) is presented, as well as preliminary calculations on hypervariable loops of two immunoglobulins (MCPC603 and Bence-Jones). © 1993 John Wiley & Sons, Inc.
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  • 20
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    Journal of Computational Chemistry 14 (1993), S. 928-933 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A new index suitable for computing molecular similarity based upon the similarity of molecular properties such as electrostatic potentials or electrostatic fields is presented in two forms. For one form of the present index, general conditions are established for which a linear measure of similarity is obtained. An illustrative example is provided in which the electrostatic field and electrostatic potential of guanine obtained from different wave functions are compared. © 1993 John Wiley & Sons, Inc.
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  • 21
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    Journal of Computational Chemistry 14 (1993), S. 934-943 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Using the MM2-87 program and parameter set, conformational analyses have been performed on cocaine (1), the potent analog 2β-carbomethoxy-3β-(4-fluorophenyl)tropane (CFT, 2), and a group of dopamine reuptake blockers that contain two phenyl rings. The latter includes LU 19-005 (3), a 1-amino-4-phenyltetralin (4), a hexahydropyrrolo[2,1-a]isoquinoline (5), diclofensine (6), and a hexahydro[1,2-b]pyridine (7). Using different values for the dielectric constant, the global minimum of 1 and 2 is a conformer in which there is a favorable electrostatic interaction between the ammonium hydrogen and the carbonyl of the carbomethoxy group. The N-methyl groups in 1 and 2 are found to strongly prefer the equatorial position of the piperidine ring. These results were also related to four crystal structures of 1 and its close derivatives. Compounds 3-7 are found to have a common conformation that was used to define the pharmacophore for dopamine reuptake blockers including the required orientation of the ammonium hydrogen. The pharmacophore provides an explanation for why the tertiary amine analogs of 3 and 4 are less potent than the secondary amines because the added N-methyl group occupies the position required for the ammonium hydrogen. This explanation, however, does not work for 7, in which the tertiary amine is again less active than the secondary amine. However, this last series appears to have a number of anomalous features. Superposition of 2 with the pharmacophore suggests that its carbomethoxy may occupy the same region of the receptor as the second phenyl ring in compounds 3-7. © 1993 John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 970-976 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The defects in atomic monopole models of molecular charge distribution have been analyzed for several model-blocked peptides and compared with accurate quantum chemical values. The results indicate that the angular characteristics of the molecular electrostatic potential around functional groups capable of forming hydrogen bonds can be considerably distorted within various models relying upon isotropic atomic charges only. It is shown that these defects can be corrected by augmenting the atomic point charge models by cumulative atomic multipole moments (CAMMs). Alternatively, sets of off-center atomic point charges could be automatically derived from respective multipoles, providing approximately equivalent corrections. For the first time, correlated atomic multipoles have been calculated for N-acetyl, N′-methylamide-blocked derivatives of glycine, alanine, cysteine, threonine, leucine, lysine, and serine using the MP2 method. The role of the correlation effects in the peptide molecular charge distribution are discussed. © 1993 John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993) 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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  • 24
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    Journal of Computational Chemistry 14 (1993), S. 1007-1018 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The program AQUARIUS2 calculates probable positions for water molecules within the first hydration shell of any protein for which atomic coordinates are known. Like its predecessor, AQUARIUS, it uses a knowledge of water molecules sites from crystallographically determined protein structures. Energy calculations are not employed. It differs substantially from the original program in that a 3-D probability map (for solvent sites) is generated around the surface of the protein instead of the previously used discrete points. The accuracy of the program has been gauged by comparison with experimentally derived water molecule positions for proteins not used in the knowledge base of the program. It has also been tested by combining the probability density maps with crystallographically determined electron density maps for the protein porphobilinogen deaminase. This procedure filters the most likely solvent electron density peaks from the background noise and has been used in the determination of the solvent structure around the protein nerve growth factor. © John Wiley & Sons, Inc.
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  • 25
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    Journal of Computational Chemistry 14 (1993), S. 1036-1041 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Net atomic charges are derived from a least-squares fitting to electrostatic potentials at atomic sites. The method treats atoms in the molecule as having spherically averaged Hartree-Fock densities, the atomic densities overlapping with one another. The method has the advantage of best reproducing the electrostatic potentials at the atomic nuclei and avoiding the arbitrariness in choosing the points used in the fitting. We have written a FORTRAN program, CHELPN92 (Z. Su, Chemistry Department, SUNY at Buffalo, Buffalo, NY, 1992), based on the method and applied it to deuterated benzene, l-alanine, d,l-histidine, 2-methyl-4-nitroaniline, and deuterated pyridinium-1-dicyanomethylide using the molecular geometry and electrostatic potentials from analysis of accurate X-ray diffraction data. The derived charges are used to calculate the molecular dipole moments. While the charges from this method are in general significantly different from those from the kappa refinement [P. Coppens, T.N. Guru Row, P. Leung, E.D. Stevens, P.J. Becker, and Y.W. Yang, Acta Cryst. A, 35, 63 (1979)], the dipole moments obtained with the new method agree well with those from the kappa refinement. © John Wiley & Sons, Inc.
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  • 26
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    Journal of Computational Chemistry 14 (1993), S. 1050-1065 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Several methods are available in the literature for the conformational analysis of small molecules. Each of these methods has some advantages and some disadvantages. Also, each of these methods may be expected to perform better or worse on different types of molecules. There is no clear calibration of each of these methods against a “standardized” set of molecules available in the literature. Such a reference work would be useful to the community because it would allow the choice of methods to be based on some facts. We attempted to provide a start to such a calibration in this article with an examination of the SYBYL SEARCH method. Methods for evaluating the performance of this method are described in detail and will be applied to all other available conformational analysis methods in future papers. © John Wiley & Sons, Inc.
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  • 27
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    Journal of Computational Chemistry 14 (1993), S. 1123-1123 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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  • 28
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    Journal of Computational Chemistry 14 (1993), S. 1125-1135 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The problem of quantifying similarity between crystal structures is transformed into the problem of comparing the associated X-ray powder diagrams. A smooth similarity measure between two powder diagrams, termed a “fold,” is defined. In contrast to conventional comparison methods, the introduced method is still applicable when the peaks of the spectra to be compared have no overlap. The main areas of application of the method are the construction of a molecular crystal structure when only the experimental powder diagram is available and the analysis of possible crystal packings predicted on the basis of molecular information only. A suitable empirical parameterization of the fold has been derived from a large set of experimental and force-field-generated crystals. The analysis of the outcome of an ab initio packing of a flexible molecule is given as an example. The algorithmic details of the method are given as a FORTRAN 77 code. © John Wiley & Sons, Inc.
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  • 29
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    Journal of Computational Chemistry 14 (1993), S. 1184-1193 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We describe a new method for de novo design of molecules that bind to protein active sites. The method, CONCEPTS (Creation of Novel Compounds by Evaluation of Particles at Target Sites), places a group of atom-like particles in the site. The particles are free to move within the site to improve binding to the protein. A key innovation of this technique is that covalent connections are made among the particles in a stochastic and dynamically reversible manner. These changes in the topology are either accepted or rejected depending on their ability to improve the total energy of the enzyme-inhibitor complex. The method is applied to two test systems: The FK506 binding protein (FKBP-12) and HIV-1 aspartyl protease. In both cases, we are able to predict, de novo, drugs that have striking similarities to known potent inhibitors and that can successfully be used to generate “hits” of the known inhibitors from a data base. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1203-1211 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The separation of the short- and long-range terms in the potentials generated by pairs of Slater functions is reformulated in the context of the Gauss transform method. Analytic expressions of the long-range potentials (in closed form) are derived for equal exponents and generalized (as expansion series) for different exponents. Additionally, the representation of these potentials from small sets of charges or lowest-order multipoles is examined, paying special attention to their values and optimal positions. Finally, numerical tests of the formal developments are presented. It is concluded that the long-range three- and four-center integrals can be calculated with high accuracy in a simple and relatively inexpensive manner. © John Wiley & Sons, Inc.
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    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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    Journal of Computational Chemistry 14 (1993), S. 1281-1289 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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    Topics: Chemistry and Pharmacology , Computer Science
    Notes: To compare the GROMOS force field with one designed by Ha et al., molecular dynamics simulations of α-D-glucose anhydrate and monohydrate crystals were performed. Also, the long-range interactions were calculated both with a cutoff approximation and with Ewald summations. The results are compared with results obtained experimentally by neutron and X-ray diffraction. The force-field parameters had been optimized with the cutoff approximation; this apparently led to worse results when the Ewald summations were used. However, in all simulations the symmetry was roughly preserved and the mean atomic coordinates and thermal parameters, bond angles, and dihedrals without hydrogen atoms were rather well reproduced. The dihedrals with hydrogen atoms exhibited conformational transitions, which resulted in a disordered hydrogen bonding scheme. In general, the GROMOS force field performed better than the Ha force field. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1301-1312 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Lithium parameters have been optimized for Stewart's standard PM3 method. The average deviation of the heats of formation calculated for 18 reference compounds is 6.2 kcal/mol from the experimental or high-level ab initio data; the average deviation with Li/MNDO is 18.9 kcal/mol. The average error in bond lengths is also reduced by a factor of two to three. Ionization potentials and dipole moments are reproduced with comparable accuracy than Li/MNDO. However, the mean deviation for the heats of formation of both methods increases when being applied to other systems, especially to small inorgnic molecules. The applicability of the new parameter set is demonstrated further for various compounds not included in the reference set, for the calculation of the activation barriers of several lithiation reactions, as well as for the estimation of oligomerization energies of methyl lithium (including the tetramer). Li/PM3 gives reliable results even for large dimeric complexes, like [{4-(CH3CR)C5H4N}Li]2, containing TMEDA or THF as coligands and reproduces the haptotropic interaction between Li+ and π-systems (e.g., in benzyl lithium) as well as the relative energies and structural features of compounds with “hypervalent” atoms (e.g., in lithiated sulfones). © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1333-1338 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: We apply a recently developed method, the multicanonical algorithm, to the problem of tertiary structure prediction of peptides and proteins. As a simple example to test the effectiveness of the algorithm, metenkephalin is studied and the ergodicity problem, or multiple-minima problem, is shown to be overcome by this algorithm. The lowest-energy conformation obtained agrees with that determined by other efficient methods such as Monte Carlo simulated annealing. The superiority of the present method to simulated annealing lies in the fact that the relationship to the canonical ensemble remains exactly controlled. Once the multicanonical parameters are determined, only one simulation run is necessary to obtain the lowest-energy conformation and further the results of this one run can be used to calculate various thermodynamic quantities at any temperature. The latter point is demonstrated by the calculation of the average potential energy and specific heat as functions of temperature. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1376-1384 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Optimized geometries and total energies for the conformers of 3,6-dihydro-1,2-dithiin (2) and 3,6-dihydro-1,2-dioxin (3) were calculated at several ab initio MO levels: RHF/3-21G(*), RHF/6-31G*, MP2/6-31G*, and MP2/6-31G*/ /RHF/3-21G(*). For the dioxin, in addition to the above levels the corresponding nonextended basis sets ab initio methods were also carried out. The dithiin results are compared with those of simple disulfanes, HSSH and (CH3)2S2, whose optimized geometries agree closely with the observed structures, which is the gauche (C2 symmetry). For the disulfanes, the gauche geometries from RHF/3-21G(*) are in good agreement with the observed structure while the RHF/3-21G results best fit the dioxin. Pertinent structural data at the RHF/3-21G(*) for the half-chair (C2) dithiin are: bond lengths, —SS—, —CS—, —CC=, and —C=C—, 2.050, 1.817, 1.515, and 1.317 Å, respectively; bond angles, CSS, =CCS, and C=CS, 98.0, 114.2, and 127.8°, respectively; CSSC dihedral angle of 63.2°; and twist angle of 36.5°. The total energy for half-chair dithiin at MP2/6-31G*//RHF/3-21G(*) is less than the planar (C2v) and the half-boat (Cs) structures by 69.67 and 29.05 kJ/mol, respectively. The calculated structural data (vs. observed) at RHF/3-21G for the half-chair dioxin are: bond lengths, —OO—, —CO—, —CC=, and C=C, 1.464 (1.463), 1.454, 1.509, and 1.313 Å (1.338 Å), respectively; bond angles, COO, =CCO, and C=CO, 105.0, 109.8 (110.3), and 120.7° (119.9°), respectively; COOC dihedral angle of 79.7° (80 ± 2°); and twist angle of 39.0 (38.3°). The total energy for half-chair dioxin at MP2/6-31G//RHF/3-21G is less than the planar and the half-boat structures by 70.35 and 42.85 kJ/mol, respectively. The total energies calculated at the extended basis sets (*) ab initio levels for the C2 symmetry dioxin are much lower than those of the nonextended basis sets. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1417-1422 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A common problem in the solution of the Poisson-Boltzmann equation using finite difference methods is the self-energy of the system, also known as the grid energy. Because atoms are typically modeled as a point charge, the infinite self-energy of a point charge is likewise modeled. In this article, a simple, alternate treatment of atomic charge is described where each atom is represented as a sphere of uniform charge. Unlike the point charge model, this method converges as the grid spacing is reduced. The uniform charge model generates the same electrostatic field outside the atoms. In addition, the use of fine grids reduces the variations in the potential due to variations in the position of atoms relative to the grid. Calculations of Born ion solvation energies, small-molecule solvation energies, and the electrostatic field of superoxide dismutase are used to demonstrate that this method yields the same results as the point charge model. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1454-1459 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An algorithm is introduced that tests whether a proposed elementary reaction can be realized within a specified number of cleavages and formations of covalent bonds. This is related to the problem of computing the minimum chemical distance of a given stoichiometry, but differs from it in important ways that are exploited in the algorithm design. One application of the algorithm is as a filter in MECHEM - a computer aid for the elucidation of reaction pathways. In that application, reaction steps implying more changes to covalent bonds than a given threshold are ruled implausible, and in practice such tests need to be carried out many thousands of times. Future applications of the algorithm can be expected because the question addressed is a fundamental one: What elementary reactions can occur? © 1993 by John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1272-1280 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: Computer methods for analytic surface calculations of molecular systems suffer from numerical instabilities and are CPU time consuming. In this article, we present proposals toward the solution of both problems. Singularities arise when nearly collinear triples of neighboring atoms or multiple vertices are encountered during the calculation. Topological decisions in analytic surface calculation algorithms (accessibility of vertices and arcs) are based upon the comparison of distances or angles. If two such numbers are nearly equal, then currently used computer programs may not resolve this ambiguity correctly and can subsequently fail. In this article, modifications in the analytic surface calculation algorithm are described that recognize singularities automatically and treat them appropriately without restarting parts of the computation. The computing time required to execute these alterations is minimal. The basic modification consists in defining an accuracy limit within which two values may be assumed as equal. The search algorithm has been reformulated to reduce the computational effort. A new set of formulas makes it possible to avoid mostly the extraction of square roots. Tests for small-and medium-sized intersection circles and for pairs of vertices with small vertex height help recognize fully buried circles and vertex pairs at an early stage. The new program can compute the complete topology of the surface and accessible surface area of the protein crambin in 1.50-4.29 s (on a single R3000 processor of an SGI 4D/480) depending on the compactness of the conformation where the limits correspond to the fully extended or fully folded chain, respectively. The algorithm, implemented in a computer program, will be made available on request. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1320-1325 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The problem of the representation of the RKR (or IPA) diatomic potential by a simple analytic function is considered. This old problem has for a fairly good solution the Coxon-Hajigeorgiou function U(x) = D[1 - exp-fn(x)]2 with fn(x) = Σm = 1n amxm. The problem of the determination of the disposable parameters a1 … an [in order that U(r) fits the given RKR potential] is reduced to that of a set of linear equations in am where a standard least-squares technique is used. The application to several states (ground or excited) of several molecules shows that a fairly “good” fit is obtained for n ∼ 10, even for the state XOg - I2 bounded by 109 vibrational levels, for which the RKR potential is defined by the coordinates of 219 points. It is shown that the percentage deviation |U(r)RKR - U(r)| throughout the range of r values is about 0.04% for XΣ—Li2, 0.0005% for XΣ—HCl, 0.06% for XOg—I2, and 0.05% for BOu—I2 (as examples). This approach shows the same success for deep and shallow potentials. The comparison of the computed Ev (vibrational energy) and Bv (rotational constant) with their corresponding experimental values shows that a good agreement is reached even for high vibrational levels close to the dissociation. © John Wiley & Sons, Inc.
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    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A description of the ab initio quantum chemistry package GAMESS is presented. Chemical systems containing atoms through radon can be treated with wave functions ranging from the simplest closed-shell case up to a general MCSCF case, permitting calculations at the necessary level of sophistication. Emphasis is given to novel features of the program. The parallelization strategy used in the RHF, ROHF, UHF, and GVB sections of the program is described, and detailed speecup results are given. Parallel calculations can be run on ordinary workstations as well as dedicated parallel machines. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1066-1076 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The nonbonded portion of a force field for lecithins was characterized by application to the study of the crystal packing geometry and energetics of eight different molecules. The molecules were either lecithin fragments or chosen to isolate particular intermolecular features to test the accuracy of the force field specifically for those interactions. In particular, the hydrocarbon interactions, hydrogen bonding, electrostatics, and phosphate interactions were critiqued. The results support previous findings that indicated that this force field is reasonably accurate for lecithins. For all molecules, a minimum was found near the experimentally determined crystal structure. Using D-glucitol as an example, it is shown that the structural effect of hydrogen bonding is better represented by a nonelectrostatic force-field model than by a purely electrostatic model. Results obtained with glycerylphosphocholine and four smaller organic phosphate molecules suggest that further study of nonbonded interactions of phosphate groups is needed. © John Wiley & Sons, Inc.
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    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
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    Journal of Computational Chemistry 14 (1993), S. 1396-1406 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An algorithm is presented within the context of the calculation of the time-relaxation behavior of the hydration shells around atomic sites in biomolecules. We report a calculation of the time-relaxation behavior of the first and second hydration shells of polar, hydrophobic, and charged groups in a protein, crambin. The water mean residence times around protein groups are obtained from averages over configurations sampled during a 325-ps molecular dynamics simulation of crambin in solution. A convolution arising in the calculation of the mean relaxation time is implemented using a parallel prefix operator. A new characterization is given of the parallel prefix operator as a linear transformation, and this formulation enables us to derive efficient factorization of the convolution as a product of two parallel prefix operations. The parallel prefix operations are implemented in logarithmic time. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1429-1439 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: The recently developed parallel coupled-cluster algorithm of Rendell, Lee, and Lindh [Chem. Phys. Lett., 194, 84 (1992)] is extended to allow four-indexed quantities containing one or two indices in the virtual orbital space to be stored across the global memory of distributed-memory parallel processors. Quantities such as the double-excitation amplitudes can now be distributed over multiple nodes, with blocks of data retrieved from remote nodes by the use of interrupt handlers. As an application of the new code, we have investigated the potential energy surface of the 2-hydroxypyridine/2-pyridone tautomers. Using large basis sets, the structure of each tautomer and the transition state connecting the two minima has been determined at the SCF level. The relative energy difference and the activation energy were then redetermined using the MP2, CCSD, and CCSD(T) methods. All calculations have been performed on Intel distributed-memory supercomputers. The largest coupled-cluster calculations contained over 2 million double-excitation amplitudes. © John Wiley & Sons, Inc.
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    Journal of Computational Chemistry 14 (1993), S. 1460-1467 
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: A method for the estimation of pKa from empirically calculated atomic charges has been developed and tested on a diverse set of organic oxyacids. The approach involves a comparison of the atomic charges calculated for both the acid and the negative ion that is formed after loss of the acidic proton. These charges have been used in conjunction with the familiar concepts of induction and resonance to develop an accurate formula to predict pKa. Results for a set of 135 compounds, including alcohols, phenols, and carboxylic acids, yielded a fit of pKa with r = 0.993 and an rms error of 0.455. © John Wiley & Sons, Inc.
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    Zeitschrift für anorganische Chemie 619 (1993), S. 381-386 
    ISSN: 0044-2313
    Keywords: Sodium tetraamido aluminate ; sodium tetraamido gallate ; crystal structure ; IR spectra ; thermal behaviour ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Redetermination of Structure and Properties of the Isotypic Sodium Tetraamido Metallates of Aluminium and GalliumCrystals for x-ray structure determination of NaAl(NH2)4 and NaGa(NH2)4 were obtained by the reaction of the metals with ammonia in autoclaves at 100°C and P(NH3) = 60 bar within 7 days. The compounds crystallize isotypic in the space group P21/c with Z = 4 NaAl(NH2)4 a = 7.328(2) Å, b = 6.047(2) Å, c = 13.151(3) Å, β = 94.04(1)° NaGa(NH2)4 a = 7.4087(8) Å, b = 6.0917(5) Å, c = 12.855(2) Å, β = 92.10(1)°The structures were refined inclusively all H-positions of the amide ions. The ternay amides are furthermore characterized by their IR spectra and their thermal behaviour.
    Notes: Für röntgenographische Strukturbestimmungen geeignete Kristalle von NaAl(NH2)4 und NaGa(NH2)4 wurden durch Umsetzung der Metalle mit NH3 in Autoklaven bei 100°C und P(NH3) = 60 bar in 7d erhalten. Die Verbindungen kristallisieren isotyp in der Raumgruppe P21/c mit Z = 4 NaAl(NH2)4 a = 7,328(2) Å, b = 6,047(2) Å, c = 13,151(3) Å, β = 94,04(1)° NaGa(NH2)4 a = 7,4087(8) Å, b = 6,0917(5) Å, c = 12,855(2) Å, β = 92,10(1)°Die Strukturen wurden einschließlich aller H-Lagen der NH2--Ionen bestimmt. Die ternären Amide werden außerdem IR-spektroskopisch und bezüglich ihres thermischen Verhaltens charakterisiert.
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  • 47
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 421-423 
    ISSN: 0044-2313
    Keywords: Barium, cobalt, erbium, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On a New Observed Dimorphism of BaCoEr2O5Single crystals of BaCoEr2O5 were prepared by CO2-LASER technique under N2-atmosphere and investigated by X-ray single crystal methods. It crystallizes with orthorhombic symmetry, space group D2h16-Pnma (a = 12.2787, b = 5.6826, c = 7.0344 Å; Z = 4). The so far unknown crystal structure of BaCoEr2O5 belongs to the BaCuLn2O5 type forming the dimorphic substance to the previously described Ni type of BaCoEr2O5.
    Notes: BaCoEr2O5 wurde mit CO2-LASER-Technik in Stickstoffatmosphäre einkristallin dargestellt und röntgenographisch untersucht. Es kristallisiert orthorhombisch, Raumgruppe D2h16-Pnma, mit den Gitterkonstanten a = 12,2787, b = 5,6826, c = 7,0344 Å; Z = 4. Die hier untersuchten Einkristalle von BaCoEr2O5 gehören zum BaCuLn2O5-Typ und bilden die dimorphe Form zum früher beschrieben Ni - Typ von BaCoEr2O5.
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  • 48
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 476-488 
    ISSN: 0044-2313
    Keywords: Dialkali metal dichalcogenides ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Dialkali Metal Dichalcogenides β-Na2S2, K2S2, α-Rb2S2, β-Rb2S2, K2Se2, Rb2Se2, α-K2Te2, β-K2Te2 and Rb2Te2The first presentation of pure samples of α- and β-Rb2S2, α- and β-K2Te2, and Rb2Te2 is described. Using single crystals of K2S2 and K2Se2, received by ammonothermal synthesis, the structure of the Na2O2 type and by using single crystals of β-Na2S2 and β-K2Te2 the Li2O2 type structure will be refined. By combined investigations with temperature-dependent Guinier-, neutron diffraction-, thermal analysis, and Raman-spectroscopy the nature of the monotropic phase transition from the Na2O2 type to the Li2O2 type will be explained by means of the examples α-/β-Na2S2 and α-/β-K2Te2. A further case of dimorphic condition as well as the monotropic phase transition of α- and β-Rb2S2 is presented. The existing areas of the structure fields of the dialkali metal dichalcogenides are limited by the model of the polar covalence.
    Notes: Die erstmalige Darstellung phasenreiner Proben von α- und β-Rb2S2, von α- und β-K2Te2 und von Rb2Te2 wird beschrieben. Mit Hilfe von ammonothermal synthetisierten Einkristallen des K2S2 und des K2Se2 wird die Struktur des Na2O2-Typs, mit Einkristallen des β-Na2S2 und des β-K2Te2 die des Li2O2-Typs verfeinert. Durch kombinierte temperaturabhängige Guinier-, Neutronenbeugungs-, thermoanalytische und Raman-spektroskopische Untersuchungen wird die Natur des monotropen Phasenübergangs vom Na2O2-Typ zum Li2O2-Typ an Hand der Beispiele α-/β-Na2S2 und α-/β-K2Te2 aufgeklärt. Ein weiterer Fall von Dimorphie, der ebenfalls monotrope Übergang von α-Rb2S2(Rb2O2-Typ) zu β-Rb2S2(Na2O2-Typ), wird vorgestellt. Die Existenzgebiete der Strukturfelder bei den Dialkalimentalldichalkogeniden werden mittels des Modells der polaren Kovalenz gegeneinander abgegrenzt.
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  • 49
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 521-524 
    ISSN: 0044-2313
    Keywords: Calcium ; bismuth ; vanadium ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of CaBiVO5Single crystals of the hitherto unknown compound CaBiVO5 were prepared and investigated by X-ray work. It crystallizes with orthorhombic symmetry, space group D2h15—Pbca, a = 11.2022, b = 5.4283, c = 15.5605 Å, Z = 8. The crystal structure is characterized by layers of the edge-linked CaO7 polyhedra, isolated VO4 tetrahedra and an asymmetric surrounding of Bi3+ by oxygen.
    Notes: Die bisher unbekannte Verbindung CaBiVO5 wurde einkristallin dargestellt und röntgenographisch untersucht. Sie kristallisiert orthorhombisch in der Raumgruppe D2h15-Pbca mit a = 11,2022, b =5,4283, c = 15,5605 Å, Z = 8. Die Kristallstruktur ist durch Schichten aus CaO7-Polyedern, isolierte VO4-Tetraeder und asymmetrisch koordinierte Bi3+-Ionen charakterisiert.
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  • 50
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 529-533 
    ISSN: 0044-2313
    Keywords: Barium-zinc-rare earth metal-oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Compounds with Zinc in Square Pyramidal Coordination: BaZnDy2O5 and Ba1.25ZnHo2O5.25 (Ba5Zn4Ho8O21).Single crystals of (I): BaZnDy2O5 and (II): Ba5Zn4Ho8O21 were prepared by high temperature reactions and investigated by X-ray technique. (I) belongs to the BaCuLn2O5 type, space group D2h16-Pbnm; a = 7.084; b = 12.368; c = 5.728 Å, Z = 4. (II) is isotypic to Ba5Mn4Ln8O21, space group C4h5-I4/m; a = 13.779; c = 5.707 Å, Z = 2. The two different structure types are caused by the small difference in the composition of 0.25 BaO. Analogies and differences will be discussed. In addition the lattice constants of powder samples of Ba5Zn4Ln8O21 (Ln = Eu, Gd, Dy, Ho, Er and Y) are given.
    Notes: Mit Hochtemperaturreaktionen wurden Einkristalle von (I): BaZnDy2O5 und (II): Ba5Zn4Ho8O21 dargestellt und röntgenographisch untersucht. (I) gehört zum BaCuLn2O5-Typ, Raumgruppe D2h16-Pbnm mit a = 7,084; b = 12,368; c = 5,728 Å, Z = 4. (II) ist isotyp zum Ba5Mn4Ln8O21-Typ, Raumgruppe C4h5-I4/m, mit a = 13,779; c = 5,707 Å, Z = 2. Der geringe Unterschied von 0,25 BaO führt zu zwei verschiedenen Strukturtypen. Gemeinsamkeiten und Unterschiede werden diskutiert. Weitere Verbindungen vom Typ Ba5Zn4Ln8O21 mit Ln = Eu, Gd, Dy, Ho, Er und Y wurden mikrokristallin dargestellt und die Gitterkonstanten bestimmt.
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  • 51
    ISSN: 0044-2313
    Keywords: Barium ; indium ; zinc ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Crystal Structure of Ba3In2Zn5O11. An Oxoindate/zincatesol;zincate with Zn10O20 and In4O16 Macropolyhedra with Zn2+ in Tetrahedral Coordination by O2-Ba3In2Zn5O11 was prepared for the first time by a flux technique and investigated by single crystal X-ray work. It crystallizes with cubic symmetry, space group T2d-F43m, a = 13.3588 Å, Z = 8. Zn2+ show tetrahedral coordination by O2-, forming Zn10O20 macropolyhedra. In addition the nZn/Osol;O part of the crystal structure is made up of Zn10O20 parts. Edge connection of four InO6 octahedra results in In4O16 groups. The crystal structure will be shown and discussed.
    Notes: Mit einer Schmelzmitteltechnik wurde erstmals Ba3In2Zn5O11 dargestellt und an Einkristallen röntgenographisch untersucht. Es kristallisiert kubisch, in der Raumgruppe T2d-F43m, mit a = 13,3588 Å und Z = 8. Zn2+ ist tetraedrisch von O2- koordiniert und bildet Zn10O20-Makropolyeder. Ferner wird der nZn/Osol;O-Teil der Kristallstruktur aus Zn10O20-Bausteinen zusammen-gesetzt. Die oktaedrisch koordinierten In3+-Ionen verknüpfen über Kanten zu In4O16-Baugruppen. Die Kristallstruktur wird vorgestellt und diskutiert.
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  • 52
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    Zeitschrift für anorganische Chemie 619 (1993), S. 617-620 
    ISSN: 0044-2313
    Keywords: Potassium ; magnesium ; copper ; vanadium ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of Potassium Magnesium Oxocuprate/-vanadate: KMg2Cu2V3O12.Single crystals of KMg2Cu2V3O12 were prepared by solid state reactions below the melting point of the reaction mixture (K2CO3, MgCO3, CuO, V2O5). It crystallizes with monoclinic symmetry space group C2h6—C2/c, a = 12.1592 Å, b = 12.7204 Å, c = 6.8557 Å, β = 111.73°, Z = 4. The structure type is characterized by VO4 tetrahedra, twisted CuO4 square units, MgO6 octahedra and a special 2 + 4 + 2 coordination around the potassium ion.
    Notes: Einkristalle von KMg2Cu2V3O12 wurden durch Feststoffreaktionen, dicht unterhalb des Schmelzpunktes des Reaktionsgemenges (K2CO3, MgCO3, CuO, V2O5), erhalten. Die Verbindung kristallisiert mit monokliner Symmetrie, Raumgruppe C2h6—C2/c, a = 12,1592 Å, b = 12,7204 Å, c = 6,8557 Å, β = 111,73°, Z = 4. Die Kristallstruktur ist durch VO4-Tetraeder, tordierte CuO4-Baugruppen, MgO6-Oktaeder und Kalium, in einer besonderen 2 + 4 + 2 Koordination charakterisiert.
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  • 53
    ISSN: 0044-2313
    Keywords: Niobum bromides ; (Nb6Br18) units ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Kristallchemie einiger neuer Niobbromide mit (Nb6Br18)-Einheiten: Die Strukturen von CsErNb6Br18 und Cs2EuNb6Br18.Zwei neue Reihen von Nb6-Bromiden, CsSENb6Br18 (SE = alle Lanthanoide außer Eu und Yb, + Y) (Typ H) und M2SENb6Br18 (M = Cs, Rb, Tl; SE = Eu, Yb) (Typ R) sind dargestellt worden. Die Kristallstrukturen von CsErNb6Br18 und Cs2EuNb6Br18, isotyp mit den entsprechenden Chloriden, wurden durch Einkristall-Röntgendaten bestimmt. Die Stabilität der (Nb6Br18)-Einheit hängt von der Art und der Ladung des Gegenkations ab. Ein Vergleich zwischen den entsprechenden Reihen der Chloride und Bromide wird anhand der chemischen Eigenschaften und der Größe des Halogens diskutiert.
    Notes: Two new series of Nb6 bromides, CsRENb6Br18 (RE = all the lanthanides excepted Eu and Yb, + Y) (type H) and M2RENb6Br18 (M = Cs, Rb, Tl; RE = Eu, Yb) (type R) have been isolated. The crystal structures of CsErNb6Br18 and Cs2EuNb6Br18, isotypic with the corresponding chlorides, have been determined by single crystal X-ray diffraction data. The (Nb6Br18) intra-unit strength is related to the nature and the charge of the counter cation. A comparison between the corresponding chlorides and bromides series, based on the chemical properties and the size of the halogen is discussed.
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  • 54
    ISSN: 0044-2313
    Keywords: Silver vanadium bronze ; copper vanadium bronze ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Novel Means of Synthesis for Vanadium Bronzes. Crystal Structure of β—Ag0.33V2O5. Refinement of the Crystal Structure of ∊—Cu0.76V2O5Ag0.33V2O5 and Cu0.76V2O5 were obtained by heating equimolar mixtures of AgI + V2O5 (700°C) and CuI + V2O5 (525°C), respectively, in sealed quartz glass ampoules. In each case, one of the well-formed crystals served for an X-ray structure analysis. Ag0.33V2O5 has the structure known of the β phase of the vanadium bronzes, i. e. layers of edge-sharing, distorted VO6 octahedra are liked by certain common octahedron vertices, the Ag atoms randomly occupy two positions with occupation probabilities of 0.5. Cu0.76V2O5 has the previously determined structure of the ∊ phase, however, its space group is not Cm but C2/m.
    Notes: Ag0,33V2O2 und Cu0,76V2O5 wurden durch zweiwöchiges Erhitzen von äquimolaren Gemischen AgI + V2O5 (700°C) bzw. CuI + V2O (525°C) in einer Quarzglasampulle erhalten. Mit je einem der gut ausgebildeten Kristalle wurden eine Röntgenstrukturanalyse durchgeführt. Ag0,33V2O5 hat die für die β-Phase der Vanadiumbronzen bekannte Struktur, d. h. Schichten aus verzerrten, kantenverknüpften VO6-Oktaedern sind über bestimmte Oktaederecken verknüpft, die Ag-Atome nehmen statistisch zwei Atomlagen der Koordinationszahl 7 mit halber Besetzungswahrscheinlichkeit ein. Cu0,76V2O5 hat die früher bereits bestimmte Struktur der ∊-Phase, deren Raumgruppe jedoch nicht Cm sondern C2/m ist.
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  • 55
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    Zeitschrift für anorganische Chemie 619 (1993), S. 281-286 
    ISSN: 0044-2313
    Keywords: Tetraphosphorus hexaoxide disulfide and trisulfide ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Improved Syntheses, Crystal Growth, and Crystal Structure Determination of P4O6S2 and P4O6S3Syntheses and single crystal growths of the title compounds are described. Both compounds crystallize in the space group P21/c (P4O6S2: a = 11.293(4); b = 6.457(3); c = 11.588(4) Å; β = 90.29(2)°, 2 450 diffractometer data, Rw = 0.035/P4O6S3: a = 15.611(5); b = 8,303(3); c = 9.697(4) Å; β = 127.12(2)°, 2 481 diffractometer data, Rw = 0.034). The structural data for the series P4O6Sn (n = 1 - 4) thus completed are compared to their oxide analogues P4O6On (n = 1 - 4). The changes in the geometry of the P4O6-cage in course of its successive oxidation are discussed.
    Notes: Darstellung und Einkristallzucht der Titelverbindungen werden beschrieben. Beide Verbindungen kristallisieren in der Raumgruppe P21/c (P4O6S2: a = 11,293(4); b = 6,457(3); c = 11,588(4) Å; β = 90,29(2)°, 2 450 Diffraktometerdaten, Rw = 0,035/P4O6S3: a = 15,611(5); b = 8,303(3); c = 9.697(4) Å; β = 127,12(2)°, 2 481 Diffraktometerdaten, Rw = 0,034). Durch die neu gelösten Strukturen werden die Daten für das System P4O6Sn (n = 1 - 4) komplettiert und können mit denen der analog aufgebauten Oxide P4O6On (n = 1 - 4) verglichen werden. Die Veränderungen der Molekülgeometrie des zentralen P4O6-Käfigs im Zuge der schrittweisen Oxidation werden diskutiert.
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  • 56
    ISSN: 0044-2313
    Keywords: Lithium thioborates ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Li5B7S13 and Li9B19S33: Two Lithium Thioborates with Novel Highly Polymeric Anion NetworksLi5B7S13 (C2/c; a = 17.304(2) Å, b = 21.922(3) Å, c = 12.233(2) Å, β = 134.91(1)°; Z = 8) and Li9B19S33 (C2/c; a = 23.669(9) Å, b = 14.361(3) Å, c = 12.237(3) Å, β = 103.77(2)°; Z = 4) were prepared by reaction of stoichiometric amounts of lithium sulfide, boron, and sulfur at 750°C (Li5B7S13) and 700°C (Li9B19S33) with subsequent annealing. The crystal structures consist of interpenetrating, polymeric boron sulfur anion networks which are formed by corner-sharing of B4S10 and B10S20 units (Li5B7S13), or B19S36 units (Li9B19S33). The lithium cations are situated in between with a strong disorder in Li9B19S33.
    Notes: Li5B7S13 (C2/c; a = 17,304(2) Å, b = 21,922(3) Å, c = 12,233(2) Å, β = 134,91(1)°; Z = 8 und Li9B19S33 (C2/c; a = 23,669(9) Å, b = 14,361(3) Å, c = 12,237(3) Å, β = 103,77(2)°; Z = 4 wurden durch Reaktion von stöchiometrischen Mengen Lithiumsulfid, Bor und Schwefel bei 750°C (Li5B7S13) und 700°C (Li9B19S33) mit anschließendem Tempern dargestellt. Die Kristallstrukturen bestehen aus sich durchdringenden, polymeren Bor-Schwefel-Anionengerüsten, die durch Eckenverknüpfung von B4S10- und B10S20-Einheiten (Li5B7S13) bzw. B19S36-Einheiten (Li9B19S33) gebildet werden. Dazwischen befinden sich die Lithiumkationen, wobei bei Li9B19S33 eine starke Fehlordnung beobachtet wird.
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  • 57
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    Zeitschrift für anorganische Chemie 619 (1993), S. 517-520 
    ISSN: 0044-2313
    Keywords: Alkaline Earth ; ruthenium ; oxygen ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Novel Oxoruthenates of the 6 L-Perovskite Type: Ba3SrRu2-xTaxO9 (x = 0.8 and 1.4) with a Comment on Ba3CaRu2O9Single crystals of the phases Ba3SrRu2-xTaxO9 [(I): x = 0.8 and (II): x = 1.4] and the compound (III): Ba3CaRu2O9 were prepared by a BaCl2 flux and investigated by X-ray methods. (I)-(III) crystallizes with hexagonal symmetry space group P62c with lattice constants: (I) a = 6.003 Å; c = 15.227 Å; (II) a = 5.988 Å; c = 15.220 Å and (III) a = 5.891 Å; c = 14.571 Å. The crystal structures of these substances corresponds to the 6 layer perovskites with the stacking sequence (hcc)2. All of them show a so far not described slightly distorted oxygen framework caused by the Sr2+ and Ca2+ ions.
    Notes: Einkristalle der Phasen Ba2SrRu2-xTaxO9 [(I): x = 0,8 und (II): x = 1,4] sowie der Verbindung (III): Ba3CaRu2O9 wurden in einer BaCl2-Schmelze präpariert und mit Hilfe von Röntgenbeugungsmethoden untersucht. (I)-(III) kristallisieren in der hexagonalen Raumgruppe P62c mit den Gitterkonstanten: (I) a = 6,003 Å; c = 15,227 Å; (II) a = 5,988 Å; c = 15,220 Å und (III) a = 5,891 Å; c = 14,571 Å. Ihre Kristallstrukturen entsprechen den 6 L-Perowskiten mit der Stapelsequenz (hcc)2. Sie zeigen eine bislang noch nicht beschriebene leichte Verzerrung im Aufbau der Sauerstoffteilgitter, die auf die Sr2+ - bzw. Ca2+-Ionen zurückgeführt werden kann.
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  • 58
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    Zeitschrift für anorganische Chemie 619 (1993), S. 525-528 
    ISSN: 0044-2313
    Keywords: Barium-bismuth-oxovanadate ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ba2BiV3O11 containing Bismuth within closed CoordinationA new barium bismuth oxovanadate, Ba2BiV3O11, was prepared and investigated by X-Ray single crystal technique. It crystallizes with monoclinic symmetry space group C2h5 - P21/a, lattice constants a = 24.6473; b = 7.7347; c = 5.6375 Å, β = 103.16°; Z = 4. Octahedra arround Bi3+, tetrahedra and double tetrahedra arround V5+ form a tunnel structure. The tunnel positions are occupied by Ba(2).
    Notes: Ein neues Barium-Bismutoxovanadat, Ba2BiV3O11, wurde einkristallin dargestellt und röntgenographisch untersucht. Es kristallisiert monoklin, Raumgruppe C2h5 - P21/a, mit den Gitterkonstanten a = 24,6473; b = 7,7347; c = 5,6375 Å, β = 103,16°; Z = 4. Oktaeder um Bi3+, Tetraeder und Doppeltetraeder um V5+ vernetzen mit Ba(1) zu einer Tunnelstruktur. Ba(2) besetzt die Tunnelpositionen.
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  • 59
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    Zeitschrift für anorganische Chemie 619 (1993), S. 534-536 
    ISSN: 0044-2313
    Keywords: Calcium ; iridium ; copper ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Ca3IrCuO6Single crystals of Ca3IrCuO6 were prepared by a flux technique and investigated by single crystal X-ray work. It crystallizes with monoclinic symmetry, space group C2h6 - C12/c1; a = 9.032, b = 9.295, c = 6.466 Å, β = 91.35°, Z = 4. Ca3IrCuO6 is isotypic to Sr3IrCuO6. The square planare CuO4 polygones show probably a slightly deficit accompanied by an adequate part of iridium in the oxydation state Ir5+.
    Notes: Einkristalle von Ca3IrCuO6 wurden mit Hilfe von Schmelzmitteln dargestellt und röntgenographisch untersucht. Es kristallisiert mit monokliner Symmetrie in der Raumgruppe C2h6 - C12/c1, mit a = 9,032, b = 9,295, c = 6,466 Å, β = 91,35°, Z = 4. Ca3IrCuO6 ist mit Sr3IrCuO6 isotyp. Die planaren CuO4-Baugruppen zeigen wahrscheinlich ein geringes Defizit an Cu2+, welches durch einen adäquaten Teil von Ir5+ kompensiert wird.
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  • 60
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    Zeitschrift für anorganische Chemie 619 (1993), S. 537-539 
    ISSN: 0044-2313
    Keywords: Sodium-barium-oxo/peroxo-aurate(III) ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the first Alkaline-Alkaline-Earth-Oxo/Peroxo-Aurate(III): NaBa4AuO4(O2)2The hitherto unknown compound NaBa4AuO4(O2)2 was prepared by oxidizing of barium gold alloy with Na2O2 in closed Ag-bombs. X-ray single crystal investigation led to tetragonal symmetry space group D4h17I4/mmm, a = 5.939; c = 15.393 Å, Z = 2. NaBa4AuO4(O2)2 shows a distorted square antiprismatic surrounding of Ba2+ by four peroxo groups on one side and four O2- on the opposite. Au3+ shows the usual square planar polygons of AuO4. Na+ is coordinated by four O2- ions in the base of an octahedron and two peroxo groups in the apical positions.
    Notes: Die bisher unbekannte Verbindung NaBa4AuO4(O2)2 wurde durch Reaktion einer Barium-Gold-Legierung mit Na2O2 im geschlossenen Silberbömbchen dargestellt. Die Kristallstruktur wurde röntgenographisch an Einkristallen untersucht. NaBa4AuO4(O2)2 kristallisiert tetragonal, Raumgruppe D4h17-I4/mmm, a = 5,939; c = 15,393 Å, Z = 2. Ba2+ ist verzerrt quadratisch antiprismatisch von vier Peroxogruppen auf der einen und vier O2--Ionen auf der Gegenseite koordiniert. Au3+ zeigt quadratisch planare Koordination von O2- und Na+ ist von vier O2--Ionen in der Oktaederbasisfläche und zwei Peroxogruppen in trans-Stellung dazu koordiniert.
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  • 61
    ISSN: 0044-2313
    Keywords: Tris(tri-tert-butylsilyl)heptaphosphonortricyclane P7(t-Bu3Si)3 ; synthesis ; 31P{1H} NMR data ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Characterization, and Structure of P7(t-Bu3Si)3 („Tris(supersilyl)heptaphosphane(3)“Tris(tri-tert-butylsilyl)heptaphosphanortricyclane P7(t-Bu3Si)3 1 is obtained from the reaction of (t-Bu)3Si—Si(t-Bu)3 with white phosphorus and forms colorless to pale yellow thermostable crystals. 1 is identified by the complete analysis of its 31P{1H} NMR spectrum (A[MX]3 spin system) as well as by a single crystal structure determination (space group Pca21, a = 170.76(2)pm, b = 131.14(3)pm, c = 426.61(5)pm, α = β = γ= 90°, Z = 8 formula units in the elementary cell). The steric demand of the (t-Bu)3Si-Groups causes an increase of the exocyclic bond angles at the equatorial phosphorus atoms Pe, while it does not particularly influence the P7-skeleton. Chlorine (r.t.) and bromine (70°C) degrade the P7-cage of 1 with formation of PX3 and (t-Bu)3SiX (X = Cl, Br).
    Notes: Tris(tri-tert-butylsilyl)-heptaphosphanortricyclan P7(t-Bu3Si)3 1 entsteht durch Umsetzung von (t-Bu)3Si—Si(t-Bu)3 mit weißem Phosphor und bildet farblose bis blaßgelbe thermostabile Kristalle. Die Identität von 1 wird durch die vollständige Analyse des 31P{1H}-NMR-Spektrums (A[MX]3-Spinsystem) sowie durch eine Kristallstrukturbestimmung belegt. 1 kristallisiert in der Raumgruppe Pca21 mit Z = 8 Formeleinheiten; a = 170,76(2)pm, b = 131,14(3)pm, c = 426,61(5)pm, α = β = γ= 90°. Der erhöhte Raumbedarf der (t-Bu)3Si-Gruppen führt zu einer Aufweitung der exocyclischen Bindungswinkel an den äquatorialen Phosphoratomen Pe ohne das P7-Gerüst besonders zu beeinflußen. Chlor (Raumtemperatur) und Brom (70°C) bauen den P7-Käfig von 1 unter Bildung von PX3 und (t-Bu)3SiX (X = Cl, Br,) ab.
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  • 62
    ISSN: 0044-2313
    Keywords: Aluminum sulfide ; crystal structure ; chemical transport ; five-coordinated aluminum ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of a Novel Hexagonal Modification of Al2S3 with Five-coordinated AluminumA new hexagonal high temperature modification of Al2S3 could be prepared by chemical vapour transport with iodine (860 → 750°C) or by annealing of α -Al2S3 at 550°C. According to the single crystal X-ray structure determination the novel form of Al2S3 crystallizes in space group P 61 (No. 169) with a = 6.491(1), c = 17.169(4) Å, V = 626.5 Å3, Z = 6; R = 0.0253. In this modification one half of the aluminum atoms are tetrahedrally coordinated [d(Al—S): 2.226-2.267 Å], whereas the other half are in trigonal bipyramidal coordination of five S atoms with bond lengths of 2.272-2.315 Å (equatorial) and 2.495-2.521 Å (axial).Aluminum in AlS5 coordination is observed for the first time in this compound. The crystal structure is isotypic to In2Se3 and AlInS3. In addition, results of a refinement of the α -Al2S3 crystal structure are reported which were obtained on crystals prepared also by chemical vapour transport with iodine.
    Notes: Eine bisher noch nicht beschriebene hexagonale Hochtemperatur-Modifikation von Al2S3 konnte in reiner Form entweder durch chemischen Transport mit Iod (860 → 750°C) oder durch Tempern von α -Al2S3 oberhalb 550°C erhalten und durch eine Einkristall-Röntgenstrukturanalyse charakterisiert werden.Die neue Form des Al2S3 kristallisiert in der Raumgruppe P 61 (Nr. 169) mit a = 6,491(1), c = 17,169(4) Å, V = 626,5 Å3, Z = 6; R = 0,0253. In dieser Modifikation liegt die eine Hälfte der Aluminiumatome tetraedrisch koordiniert vor [d(Al—S): 2,226-2,267 Å], während die andere Hälfte trigonal-bipyramidal von fünf S-Atomen mit Al—S-Bindungslängen von 2,272 bis 2,315 Å (äquatorial) und 2,495-2,521 Å (axial) umgeben ist.Aluminium in AlS5-Koordination ist bisher unbekannt und wird hier zum ersten Mal beobachtet. Die Struktur ist isotyp zu In2Se3 und AlInS3. Zusätzlich wird über die Verfeinerung der Kristallstruktur α von -Al2S3 an Einkristallen berichtet, die ebenfalls durch chemischen Transport mit Iod hergestellt wurden.
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  • 63
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1004-1006 
    ISSN: 0044-2313
    Keywords: Alkaline-Earth ; palladium ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On an Alkaline-Earth Oxopalladate containing Pd6O12 Rings: CaBa2Pd3O6CaBa2Pd3O6 was prepared for the first time and investigated by X-ray single crystal technique. It is isotypic to NaBa2Cu3O6 and crystallizes with orthorhombic symmetry, space group D2h23-Fmmm, a = 8.717, b = 11.47, c = 14.933 Å; Z = 2. Typical features of the crystal structure are edge connected square planar PdO4 polygones, forming isolated Pd6O12 rings.
    Notes: CaBa2Pd3O6 wurde erstmals dargestellt und röntgenographisch an Einkristallen untersucht. Es ist isotyp mit NaBa2Cu3O6 und kristallisiert mit orthorhombischer Symmetrie, Raumgruppe D2h23-Fmmm, a = 8,717, b = 11,47, c = 14,933 Å; Z = 2. Charakteristische Strukturmerkmale sind kantenverknüpfte planare PdO4-Polygone, die isolierte Pd6O12-Ringe ausbilden.
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  • 64
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1012-1016 
    ISSN: 0044-2313
    Keywords: Zwitterionic λ5-organofluorosilicate ; pentacoordinate silicon ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal and Molecular Structure of Tetrafluoro[2-(pyrrolidinio)ethyl]silicateThe zwitterionic tetrafluoro[2-(pyrrolidinio)ethyl]silicate (4) was synthesized by reaction of trimethoxy(2-pyrrolidinoethyl)silane (5) with hydrogen fluoride in ethanol/hydrofluoric acid at 0°C. The crystal and molecular structure of 4 was studied at -100°C by single-crystal X-ray diffraction. In addition, 4 was characterized by solution-state NMR studies (CD3CN: 1H, 13C).
    Notes: Das zwitterionische Tetrafluoro[2-(pyrrolidinio)ethyl]silicat (4) wurde durch Reaktion von Trimethoxy(2-pyrrolidinoethyl)silan (5) mit Fluorwasserstoff in einem Ethanol/Flußsäure-Gemisch bei 0°C synthetisiert. Die Kristall- und Molekülstruktur von 4 wurde bei - 100°C mittels einer Einkristall-Röntgenstrukturanalyse untersucht. Außerdem wurde 4 durch NMR-Untersuchungen in Lösung charakterisiert (CD3CN: 1H, 13C).
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  • 65
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1017-1022 
    ISSN: 0044-2313
    Keywords: Thallium perrhenate ; room-temperature modification ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die Kristallstruktur von β-ThalliumperrhenatDie Raumtemperaturmodifikation von Thalliumperrhenat, β-TlReO4, wurde durch Röntgenbeugung an Einkristallen untersucht. β-TlReO4 kristallisiert in der monoklinen Raumgruppe P1121/a mit a = 5,636(1), b = 17,428(3), c = 13,353(3) Å, γ = 89,86(2)° und Z = 12. Die Strukturverfeinerung endete bei R = 0,063 (wR = 0,053), wobei 2 020 absorptionskorrigierte Reflexdaten verwendet wurden. β-TlReO4 läßt sich als eine Verwachsung von β-CsReO4- und Scheelit-Einheiten auf Elementarzellniveau beschreiben.Die Struktur von β-TlReO4, besteht aus isolierten ReO4-Tetraedern, die durch TlO8- und TlO9-Polyeder miteinander verknüpft sind. Auf der Basis gruppentheoretischer Überlegungen werden die strukturellen Beziehungen zwischen β-TlReO4, β-CsReO4, α-CsReO4 und Scheelit-Typ diskutiert.
    Notes: β-TlReO4, the room temperature modification of thallium perrhenate, has been investigated by means of single crystal X-ray diffraction. It crystallizes in the monoclinic space group P1121/a with a = 5.636(1), b = 17.428(3), c = 13.353(3) Å, γ = 89.86(2)° and Z = 12. The structure has been refined to R = 0.063 (wR = 0.053) using 2 020 absorption-corrected reflections. The title compound can be described as an intergrowth of β-CsReO4 and scheelite type blocks at unit cell level. The structure of β-TlReO4 consists of isolated ReO4 tetrahedra linked together by TlO8 and TlO9 polyhedra. Based upon group theoretical considerations the structural relationships between β-TlReO4, β-CsReO4, α-CsReO4 and scheelite type are discussed.
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  • 66
    ISSN: 0044-2313
    Keywords: Polysulfonyl amines ; silver(1) dimesylarnide ; tetrakis(dimesylamido)aquatetrasilver(l) ; crystal structure ; thermal analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polysulfonyl Amines. XLI. A Silver(I) Hydrate with an Unusual Composition: Characterization of Tetrakis(dimesylamido)aquatetrasilver(I) [Ag4(N)SO2CH3)2}4(H2O)] by X-Ray Diffraction and Thermal AnalysisThe title compound is obtained by crystallizing AgN(SO2CH3)2 from water at room temperature. Crystallographic data (at -95°C): Triclinic space group P1, a = 864.6(4), b = 1 211.2(5), c = 1 399.1(5) pm, α = 90.97(3), β = 90.90(3), γ = 98.25(4)°, V = 1.4496 nm3, Z = 2, Dx = 2.608 Mg m-3. The four independent silver atoms and the water molecule form zigzag chains Ag(1)-Ag(2)-(μ-H2O)-Ag(3) … Ag(4) … Ag(1′) with distances Ag(1)-Ag(2) 309.7, Ag(2)-O(w) 241.8, O(w)-Ag(3) 241.4, Ag(3) … Ag(4) 342.9, Ag(4) … Ag(1′) 361.4 pm. The catenated silver atoms are further connected by the dimesylamide anions acting as tridentate bridging (α-O, N, ω-O)-ligands. The resulting strands are interconnected into layers through one O(S)-Ag′ contact (247 pm) and one hydrogen bond O(w)-H(l) … O′(S) per repeating unit. Between the layers, a weak O(S) … Ag″ interaction (271 ptn) and a hydrogen bond O(w)-H(2) … O(S) per repeating unit are observed. The silver atoms Ag(l) to Ag(4) display the coordination numbers 5 [NO,Ag(2), distorted trigonal bipyramid], 5[NO2,O(w)Ag(I), distorted trigonal bipyramid], 5[O4,O(w), trigonal bipyramid], and 2 + 1 (N2, li-near; plus a secondary Ag … 0 contact). The dehydration of the title compound and a solid-solid phase transformation in anhydrous AgN(SO2CH3)2, were quantitatively investigated by thermoconductometry and time- and temperature-resolved X-ray diffractometry (TXRD).
    Notes: Die Titelverbindung entsteht durch Kristallisation von AgN(SO2CH3)2 aus Wasser bei Raumtemperatur. Kristallographische Daten (bei -95°C): Trikline Raumgruppe P1, a = 864,6(4), b = 1 211,2(5), c = 1 399,1(5) pm, α = 90,97(3), β = 90,90(3), γ = 98,25(4)°, V = 1,4496 nm3, Z = 2, Dx = 2,608 Mg m-3. Die vier unabhängigen Silberatome und das Wassermolekül bilden Zickzack-Ketten Ag(1)-Ag(2)-(μ-H2O)-Ag(3) … Ag(4) … Ag(1′) mit den Abständen Ag(1)-Ag(2) 309,7, Ag(2)-O(W) 241,8 O(W)-Ag(3) 241,4, Ag(3) … Ag(4) 342,9, Ag(4) … Ag(1′) 361,4 pm. Die Silberatome in der Kette werden durch die Dimesylamid-Anionen miteinander verklammert, die innerhalb der so resultierenden Stränge als dreizähnig-verbrückende (α-O, N, ω-O)-Liganden wirken. Die Stränge sind pro Repetiereinheit durch einen Kontakt O(S)-Ag′ (247 pm) und eine Wasserstoffbrücke O(W)-H(1) …O′(S) zu Schichten verknüpft. Zwischen den Schichten bestehen je Strang-Repetiereinheit eine schwache Wechselwirkung O(S) … Ag″ (271 pm) und eine Wasserstoffbrücke O(W)-H(2) … O″(S). Die Silberatome besitzen in der Reihenfolge Ag(1) bis Ag(4) die Koordinationszahl 5 [NO3Ag(2), verzerrt trigonal-bipyramidal], 5 [NO2O(W)Ag(1), verzerrt trigonal-bipyramidal], 5 [O4O(W), trigonal-bipyramidal], 2 + 1 (N2, linear; ein zusätzlicher Sekundärkontakt Ag … O). Die Dehydratation der Titelverbindung und eine fest-fest-Phasenumwandlung des wasserfreien AgN(SO2CH3)2 wurden durch Thermokonduktometrie sowie zeit- und temperaturaufgelöste Röntgendiffraktometrie (TXRD) quantitativ untersucht.
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  • 67
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1037-1046 
    ISSN: 0044-2313
    Keywords: Nickel ; chromium ; molybdenum ; penicillamine ; complexes ; synthesis ; crystal structure ; antidot ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Penicillamine Complexes of Nickel, Chromium, and Molybdenum  -  Structural Particularity and Biological/Medical RelevanceThe compounds Tl2[NiII(H2O)6][NiII(D-pen)(L-pen)]2[NiII(SCN)2(H2O)4] 1, Tl[NiII(D-pen)2H] · H2O 2, Tl[CrIII(D-pen)2] 3, and Na2[Mo2VO4(pen)2] · 3 CH3OH · 3 H2O 4 have been prepared by the reaction of nickel nitrate (for 1), nickel acetate (for 2), potassium chromate (for 3), and sodium molybdate (for 4) with D- and D, L-penicillamine, respectively. They were characterized by single-crystal X-ray structure analysis and other physical methods. Whereas penicillamine acts as a bidentate (N, S)-ligand in 1 and 2, CrIII (in 3), and MoV (in 4) are coordinated to the three ligand atoms N, O, and S. The presence of three different types of NiII-complexes a cationic, a neutral, and an anionic one in 1 is remarkable.For crystal data see Inhaltsübersicht.
    Notes: Die Verbindungen Tl2[NiII(H2O)6][NiII(D-Pen)(L-Pen)]2[NiII(SCN)2(H2O)4] 1, Tl[NiII(D-Pen)2H] · H2O 2, Tl[CrIII(D-Pen)2] 3 und Na2[Mo2VO4(Pen)2] · 3 CH3OH · 3 H2O 4 wurden durch Umsetzung von Nickelnitrat (für 1), Nickelacetat (für 2), Kaliumchromat (für 3) und Natriummolybdat (für 4) mit D- bzw. D, L-Penicillamin in wäßriger Lösung dargestellt und durch Einkristallstrukturanalyse und andere physikalische Methoden charakterisiert. Während in den Ni-Pen-Komplexen von 1 und 2 Penicillamin als zweizähniger Ligand (N, S) fungiert, sind CrIII in 3 und MoV in 4 über N, O und S koordiniert. Bemerkenswert ist, daß in 1 drei verschiedene Ni-Komplexe und zwar ein kationischer, ein neutraler und ein anionischer in einer Elementarzelle vorliegen.1: C2/m, a = 1 484,6(4), b = 1 358,7(4), c = 1 204,7(3) pm, β = 103,75(2)°, V = 2 360,4(11) ° 106 pm3, R = 0,042 für 1 633 unabhängige Reflexe (Fo〉 4,0σ(Fo)), Z = 2.2: C2, a = 2 279,9(7), b = 613,1(1), c = 1 275,2(3) pm, β = 110,94(2)°, V = 1 664,8(6) · 106 pm3, R = 0,056 für 1 413 unabhängige Reflexe (Fo〉 4,0σ(Fo)), Z = 4.3: C2, a = 2 054,0(3), b = 592,1(1), c = 606,7(1) pm, β = 92,89(1)°, V = 736,95(17) · 106 pm3, R = 0,028 für 862 unabhängige Reflexe (Fo〉 4,0σ(Fo)), Z = 2.4: P1, a = 996,2(4), b = 1 222,2(7), c = 1 395,3(7) pm, = 114,27(4), β = 104,55(4), γ = 95,63(4)°, V = 1 459,4(13) · 106 pm3, R = 0,072 für 3 763 unabhängige Reflexe (Fo〉 4,0σ(Fo)), Z = 2.
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  • 68
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1073-1082 
    ISSN: 0044-2313
    Keywords: Bismuth arene π-complexes ; bismuth xylene complexes ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heavy Metal π-Complexes. IX. The Chain Polymers ∞1[(1,2- (CH3)2C6H4BiCl3)2], ∞1[(1,3- (CH3)2C6H4BiCl3)2] and ∞1[(1,4- (CH3)2C6H4BiCl3)2]In the crystal structures of the three solid state complexes (C6H4(CH3)2BiCl3 (C6H4(CH3)2 = o-xylene: 1, m-xylene: 2, p-xylene: 3) quasi-dimeric units of almost undistorted, arene coordinated BiCl3 fragments can be found that are further associated via additional Bi—Cl contacts to form one-dimensional polymeric chains. Whereas the chains of 2 and 3 are constituted by Bi2Cl2 four-membered rings only, further Cl-bridging in 1 leads to additional trigonal-bipyramidal arrangements with Bi atoms exhibiting coordination numbers of 3 + 3 + 1 and 3 + 2 + 1, respectively (prim. + sec. Cl contacts + arene). The arene-metal bonding is characterized by Bi-arene distances in the range from 297 - 306 pm, including ring slippages of 24 -41 pm and 73 pm with the Bi atoms being six and seven coordinated, respectively. The direction of this slipping with respect to the arene's methylation sites cannot be understood in terms of electronic influences but is shown to be caused by steric demands. The values IP1 of the arenes prove to determine the colours of the complexes.
    Notes: In den Festkörperstrukturen der drei Komplexe (C6H4(CH3)2)BiCl3 (C6H4(CH3)2 = o-Xylol: 1, m-Xylol: 2, p-Xylol: 3) findet man quasidimere Einheiten fast unverzerrter, arenkoordinierter BiCl3-Fragmente, die über zusätzliche Bi—Cl-Kontakte zu eindimensionalen polymeren Ketten assoziiert sind. Während die Ketten von 2 und 3 nur aus Bi2Cl2-Vierringsegmenten bestehen, führt eine weitere Verbrückung in 1 zusätzlich zu trigonal-bipyramidalen Anordnungen mit Bi-Atomen der Koordinationszahlen 3 + 3 + 1 bzw. 3 + 2 + 1 (prim. + sek. Cl-Kontakte + Aren). Die Bindung des Arens an das Metall ist durch Bi-Aren-Abstände zwischen 297 und 306 pm charakterisiert. Die „ring slippage“ beträgt 24-41 bzw. 73 pm bei den sechsfach bzw. siebenfach koordinierten Bi-Atomen. Die Richtung dieser Verschiebung in bezug auf die Lage der Methylgruppen des Arens kann nicht auf elektronischer Basis interpretiert werden, sondern ist sterisch verursacht. Für die Farbe der Komplexe erweist sich IP1 des Arens als bestimmend.
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  • 69
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1147-1153 
    ISSN: 0044-2313
    Keywords: O,O′,O″,O‴-tetraphenyl μ-imido-dithiodiphosphate ; N-(O,O′-diphenylthiophosphoryl)-O″,O‴-diphenylthiophosphorimidate ; Bis(O,O′,O″,O‴-tetraphenyl μ-imido-dithiodiphosphato) palladium chelate ; Bis[N-O,O′-diphenylthiophosphoryl-O″,O‴-diphenylthiophosphorimidato] palladium chelate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Der Tetraphenylester der μ-Imido-dithiodiphosphorsäure und sein Palladiumkomplex  -  KristallstrukturenDie Darstellung der Verbindung [(C6H5O2PS]2NH (SS) und ihres Palladiumkomplexes [Pd{C6H5O)2P(S)NP(S)(OC6H5) 2}2] (PDSS) wird beschrieben. Die Verbindungen werden elementaranalytisch, durch NMR- und Massenspektrometrie sowie mittels Röntgen-Kristallstrukturanalyse charakterisiert. Die Struktur von SS enthält zwei unabhängige Moleküle in einer asymmetrischen Einheit, die über N … H … S Wasserstoffbrücken zu Dimeren verbunden sind. SS ist eine Br⊘nsted-Säure, die mit PdII zu einem neutralen Chelatkomplex reagiert. Die Struktur von PDSS besteht aus isolierten Molekülen mit dem Pd-Atom als Symmetriezentrum. Das Pd ist an 4 S-Atome in einer verzerrt quadratisch-planaren Anordnung mit einem mittleren Abstand Pd—S von 2,345(6) Å und Winkel S—Pd—S von 98,29(4)° gebunden.
    Notes: The preparations of [(C6H5O)2PS]2NH (SS) and its Pd complex [Pd{C6H5O2P(S)NP(S)(OC6H5) 2}2] (PDSS) are described. The compounds were characterized by elemental analysis, NMR, and mass spectra and X-ray structure analysis. The structure of SS contains two independent molecules in an asymmetric unit which are joined into dimers via N … H … S hydrogen bonds. SS is a Br⊘nsted acid And reacts with PdII to a neutral chelate complex. The structure of PDSS is composed of isolated molecules with Pd atom in the center of symmetry. The Pd atom is coordinated by 4 S atoms in a distorted square-planar arrangement with average distance Pd—S 2.345(6) Å and an angle S—Pd—S 98.29(4)°.
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  • 70
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1132-1136 
    ISSN: 0044-2313
    Keywords: Hexamolybdotellurate(VI) ; crystal structure ; hydrogen bonding ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Über das Protonenakzeptorverhalten von [TeMo6O24]6- in Na4(NH4)2[TeMo6O24] · 16H2OFarblose Einkristalle von Na4(NH4)2[TeMo6O24] · 16H2O wurden in wäßriger Lösung gezüchtet (Raumgruppe P1, a = 1 075,3(1), b = 1 074,2(1), c = 1 089,8(1) pm, = 96,259(9), β = 118,556(7), γ = 113,355(8)°, Z = 1, 295 K, 311 Parameter, 3 689 Reflexe, Rg = 0,0197). Es liegen zwei kristallographisch unabhängige Na+ Kationen vor. Na(1) ist oktaedrisch von vier Wassermolekülen und zwei Sauerstoffatomen des zentrosymmetrischen [TeMo6O24]6--Anions umgeben. Na(2) ist in stark verzerrt trigonal-bipyramidaler Weise von fünf Wassermolekülen koordiniert. Je zwei dieser Na(H2O)5+-Bipyramiden sind mit zwei NH4+-Kationen über Wasserstoffbrückenbindungen zu zentrosymmetrischen kationischen Clustern verknüpft. Mit Ausnahme von O(10) wirken alle Sauerstoffatome des [TeMo6O24]6--Anions ungeachtet ihrer unterschiedlichen Bindigkeit bezüglich Mo bzw. Te als annähernd gleichwertige Protonenakzeptoren in Wasserstoffbrückenbindungen zu den NH4+-Kationen und den Kristallwassermolekülen.
    Notes: Colourless triclinic single crystals of Na4(NH4)2[TeMo6O24] · 16H2O were grown in aqueous solution (space group P1, a = 1 075.3(1), b = 1 074.2(1), c = 1 089.8(1) pm, = 96.259(9), β = 118.556(7), γ = 113.355(8)°, Z = 1, 295 K, 311 parameters, 3 689 reflections, Rg = 0.0197). There are two crystallographically independent Na+ cations. Na(1) is coordinated octahedrally by four water molecules and two oxygen atoms of the centrosymmetric [TeMo6O24]6- anion. Na(2) is bound to five water molecules in a considerably distorted trigonally bipyramidal fashion. These bipyramids are linked with NH4+ by hydrogen bonds to yield centrosymmetric cluster cations consisting of two NH4+ and two Na(H2O)5+ each. Hydrogen bonds envolving all except one (O(10)) of the oxygen atoms of the [TeMo6O24]6- anion as almost equivalent proton acceptors regardless of their bonding mode to Te and Mo, respectively, establish further connections to NH4+ and the water of crystallization.
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  • 71
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1137-1146 
    ISSN: 0044-2313
    Keywords: Molybdotellurate(VI) ; crystal structure ; differential thermal analysis ; hydrogen bonding ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Wasserreiche Molybdotellurate: Darstellung und Kristallstruktur von Li6[TeMo6O24] · 18 H2O und Li6[TeMo6O24] · Te(OH)6 · 18 H2OLi6[TeMo6O24] · 18 H2O kristallisiert in der triklinen Raumgruppe P1 (a = 1 041,7(1), b = 1 058,6(1), c = 1 070,8(1) pm, α = 61,08(1), β = 60,44(1), γ = 73,95(1)°. Die Einkristallröntgenstrukturanalyse (Z = 1, 295 K, 317 Parameter, 3 973 Reflexe, Rg = 0,0250) zeigte, daß eine verzweigte, unendliche Kette aus kantenverknüpften Li-Koordinationspolyedern das markante Strukturmerkmal dieser Verbindung ist. Eines der vier kristallographisch unabhängigen Li+-Kationen ist oktaedrisch koordiniert. Bei den übrigen Li+-Kationen liegt verzerrt trigonal-bipyramidale Koordination vor. Lediglich drei kristallographisch unabhängige Sauerstoffatome (O(9), O(10), O(12)) des zentrosymmetrischen [TeMo6O24]6--Anions sind an Li+ koordiniert. Die übrigen Positionen in den Li+-Koordinationssphären sind durch Wassermoleküle besetzt. Die Sauerstoffatome des [TeMo6O24]6--Anions treten in intermolekularen Wasserstoffbrückenbindungen ungeachtet ihrer unterschiedlichen Bindigkeit bezüglich Mo und Te als annähernd gleichwertige Protonenakzeptoren auf.Li6[TeMo6O24] · Te(OH)6 · 18 H2O kristallisiert in der monoklinen Raumgruppe P21/n mit Z = 4, a = 994,1(3), b = 2 344,8(10), c = 1 764,9(4) pm und β = 91,36(4)°. Die Einkristallröntgenstrukturbestimmung mit 627 Parametern und 5900 Reflexen (295 K) konvergierte bei Rg = 0,0324. Es liegen sechs kristallographisch unabhängige Li+-Kationen vor. Die Koordinationspolyeder von Li(1), Li(2), Li(3) und Li(4) sind über gemeinsame Kanten zu einem achtgliedrigen, zentrosymmetrischen Strang verknüpft. Die Koordinationspolyeder von Li(5) und Li(6) sind über eine gemeinsame Ecke zu Zweiergruppen verbunden. Sämtliche Sauerstoffatome des eingeschlossenen Te(OH)6-Moleküls, aber nur drei Sauerstoffatome (0(13), 0(18), O(23)) des [TeMo6024]6--Anions, welches hier über keine kristallographische Symmetrie verfügt, sind an Li+ koordiniert. Die Sauerstoffatome des Anions treten in Wasserstoffbrückenbindungen von überwiegend mittlerer Stärke als Protonenakzeptoren auf. Kurze intermolekulare Wasserstoffbrückenbindungen verbinden die [TeMo6O24]6--Anionen mit den Te(OH)6-Molekülen zu unendlichen Ketten.
    Notes: Li6[TeMo6O24] · 18 H2O is triclinic (space group P1, a = 1 041.7(1), b = 1 058.6(1), c = 1 070.8(1) pm, α = 61.08(1), β = 60.44(1), γ = 73.95(1)°). Single crystal X-ray structure analysis (Z = 1, 295 K, 317 parameters, 3 973 reflections, Rg = 0.0250) revealed an infinite branched chain of edge-sharing Li coordination polyhedra to be the prominent structural feature. One of the four crystallographically independent Li+ is coordinated octahedrally. The coordination polyhedra of the remaining Li+ are distorted trigonal bipyramids. Only three unique oxygen atoms (O(9), O(10), O(12)) of the centrosymmetric [TeMo6O24]6- anion are bound to Li+. The further positions in the coordination spheres of the Li+ are occupied by water molecules. Intermolecular hydrogen bonds involve mainly oxygen atoms of the [TeMo6O24]6- anion as nearly equivalent proton acceptors without regard to their different bonding modes to Te and Mo, respectively.Li6[TeMo6O24] · Te(OH)6 · 18 H2O crystallizes monoclinically in space group P21/n with Z = 4, a = 994.1(3), b = 2 344.8(10), c = 1 764.9(4) pm, and β = 91.36(4)°. Single crystal structure analysis with least squares refinement of 627 parameters (5 900 reflections, 295 K) converged to Rg = 0.0324. There are six unique Li+ cations. The coordination polyhedra of Li(1), Li(2), Li(3), and Li(4) are linked by common edges to yield an eight membered centrosymmetric strand. The coordination polyhedra of the remaining two Li+ sites (Li(5), Li(6)) are connected to a dimeric unit via a common corner. All oxygen atoms of the Te(OH)6 molecule are involved in the coordination of Li+. However, only three oxygen atoms (O(13), O(18), O(23)) of the [TeMo6O24]6- anion which lacks crystallographic symmetry are involved in the coordination of Li+. The oxygen atoms of the anion act as proton acceptors in hydrogen bonds of predominantly medium strength. Te(OH)6 molecules and [TeMo6O24]6- anions connected by strong hydrogen bonds form an infinite chain.
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  • 72
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1155-1160 
    ISSN: 0044-2313
    Keywords: Tin tetrathalliumtritelluride ; lead tetrathalliumtritelluride ; preparation ; crystal structure ; Cr5B3 type ; In5Bi3 type ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Crystal Structure of SnTl4Te3 and PbTl4Te3.We describe the synthesis and crystal structure of two ternary derivatives MTl4Te3 of the parent phase Tl5Te3. Both the derivatives, SnTl4Te3 and PbTl4Te3, crystallize with the In5Bi3 type of structure: space group I4/mcm, Z = 4. The cell constants of SnTl4Te3(PbTl4Te3) are as follows: a = 8.819(2) Å (8.841(2)Å), c = 13.013(3) Å (13.056(3) Å), c/a = 1.47 (1.48). Short M—Te distances of 3.25 Å (3.26 Å) are obtained in ∞1[MTe2/2] chains, which run along [001]. The M atoms are further surrounded by additional tellurium atoms in such a way that octahedra occur, which share common vertices to build up a three dimensional infinite network ∞3[MTe6/2]. The remaining thallium atoms span cubes around the octahedra: ∞3[MTe6/2]Tl8/2 = MTl4Te3.An alternative structure description takes into account bent fragments Tl2Te with Tl—Te distances of 3.15 Å (3.17 Å) as the constitutional elements of M-centered, slightly distorted rhombic dodecahedra as the only polyhedra of the structure. Along [001] they share common vertices, whereas in the tetragonal a-a-plane they are interconnected via common faces.
    Notes: Die Darstellung und die Kristallstruktur der zwei ternären Abkömmlinge SnTl4Te3 und PbTl4Te3 werden beschrieben. Beide kristallisieren isotyp zu ihrer Mutterphase Tl5Te3 im In5Bi3-Typ, der seinerseits eine isopuntale Unterfamilie des Cr5B3-Typs bildet. Die Raumgruppe ist I4/mcm, die Zahl der Formeleinheiten beträgt 4. Die Gitterkonstanten für SnTl4Te3(PbTl4Te3) lauten a = 8,819(2) Å (8,841(2) Å), c = 13,013(3) Å (13,056(3) Å), das c/a-Verhältnis beträgt 1,47 (1,48).In zwei Fragmenten des dreidimensionalen Verbandes treten kurze M—Te—Abstände auf (M = Sn, Pb, Tl). Je nachdem, welchem Fragment man mehr Aufmerksamkeit schenkt, sind zwei alternative, aber gleichwertige Strukturbeschreibungen möglich: Die erstere lehnt sich an die bei der Mutterphase Tl5Te3 gewählte an und betont die kurzen Sn—Te— bzw. Pb—Te—Abstände in den parallel zur [001]-Richtung verlaufenden linearen Ketten ∞1[MTe2/2](Sn—Te: 3,25 Å, Pb—Te: 3,26 Å). Die M-Atome der Ketten werden durch weitere Tellur-Atome zu einem allseits spitzenverknüpften Oktaederverband ∞1[MTe6/2] komplettiert. Die Oktaeder werden würfelförmig von den Thallium-Atomen umgeben: ∞3[MTe6/2]Tl8/2 = MTl4Te3.De zweite betont die gewinkelten Fragmente Tl2Te(Tl—Te in SnTl4Te3: 3,15 Å, Tl—Te in PbTl4Te3: 3,16 Å). Die Tl2Te-Fragmente sind Teile verzerrter Tl2Te2-Rhomben. Diese Rhomben bauen M-zentrierte Rhombendodekaeder auf (M = Sn, Pb), die das einzige zum Strukturaufbau nötige Polyeder sind.
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  • 73
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1177-1182 
    ISSN: 0044-2313
    Keywords: 3, 5-Dimethyl-4-oxo-4-phenoxy-1 λ4-thia-2, 3,-5, 6-tetraaza-4λ5-phosphacyclohexane-2, 6-dicarbonic acid diethylester ; 3, 5-Dimethyl-4-phenoxy-4-thioxo-1λ4-thia-2, 3, 5, 6-tetraaza-4λ5-phosphacyclohexane-2, 6-dicarbonic acid diethylester ; crystal structure ; NMR spectra ; twist-boat conformation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus(V)-Hydrazine-Sulfur(IV) Heterocycles with Twist-Boat Conformation.Unlike the corresponding unsubstituted compounds N-ethoxycarbonyl-substituted dihydrazidophosphoric acid derivatives do not react with thionylchloride under redoxdecomposition but yield sulfur containing sixmembered rings. In solution (NMR spectra) as well as in the crystal (X-ray structure analysis) the rings adopt unusual twist-boat conformations. Due to the rather bulky substituents high energies of interconversion between enantiomeric twist-forms are found: 75 ± 2 kJ/mol.
    Notes: N-ethoxycarbonyl-substituierte Dihydrazidoderivate der Phosphorsäure reagieren mit Thionylchlorid nicht wie die entsprechenden unsubstituierten Verbindungen unter Redoxzersetzung sondern unter Bildung schwefelhaltiger Sechsringe. Die Ringe liegen sowohl in Lösung (NMR-Spektren) als auch im Kristall (Röntgenstrukturanalyse) in einer ungewöhnlichen Twist-Boot-Konformation vor. Bedingt durch die sperrigen Substituenten ergeben sich hohe Aktivierungsenergien für die Interkonversion der enantiomeren Twistkonformationen von 75 ± 2 kJ/mol.
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  • 74
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1203-1208 
    ISSN: 0044-2313
    Keywords: β-Sodium thiocarbonate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Modified Synthesis and Crystal Structure Determination of β-Na2CS3.β-Na2CS3 has been synthesized via a novel route from Na2S and CS2, and its crystal structure has been determined using single crystal techniques (for crystallographic informations see “Inhaltsübersicht”). Structural relations between Li2CO3 and β-Na2CS3 are discussed. The ionic conductivities are 3 · 10-11S cm-1 and 1.3 · 10-2S cm-1 at 50°C and 250°C, respectively.
    Notes: In der Literatur als β-Na2CS3 beschriebenes Natriumthiocarbonat wurde auf einem neuen Wege aus Na2S und CS2 dargestellt und die Kristallstruktur aufgeklärt (C2/c; a = 1 003,6(1) pm, b = 633,7(1) pm, c = 855,5(1) pm, β = 108,05(1)°, Z = 4,1582 unabhängige Reflexe, R = 0,034). Strukturbeziehungen zu Li2CO3 werden diskutiert. Die Ionenleitfähigkeiten betragen 3 · 10-11S cm-1 und 1,3 · 10-2S cm-1 bei 50°C bzw. 250°C.
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  • 75
    ISSN: 0044-2313
    Keywords: Complex compounds ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Crystal Structures and Spectroscopic Investigations of 3d-Transition Metal Complexes with Bicyclo[2.2.1]hept-5-ene-2-endo,3-cis-dicarboxylic Acid and N,N-Donor LigandsThe synthesis of coordination compounds of the general type [MLdam(H2O)3] · 2.5 H2O with M = Mn2+, Co2+, Ni2+; H2L = bicyclo[2.2.1]hept-5-ene-2-endo,3-cis-dicarboxylic acid and dam = 2,2′-dipyridyl, 1,10-phenanthroline has been described. The complexes have been characterized by elementary analysis, infrared and electronic spectra and magnetic susceptibility measurements.The results of X-ray crystal structure analyses of [MnLdipy(H2O)3] · 2.5 H2O (1 a) and [CoLdipy(H2O)3] · 2,5 H2O (1 b) show, that both compounds crystallize isotypically and prove the octahedral coordination of the metal atoms. The dicarboxylate anion is coordinated to the central atom by an O atom of only one carboxylate group, the other one is in the ionic state. One O atom of each carboxylate group makes an intramolecular hydrogen bond with a water molecule of the coordination sphere. The other crystal water molecules form a network of H bonds one with another and with the complex molecules, thus stabilizing the crystal packing.
    Notes: Die Synthese von Koordinationsverbindungen der allgemeinen Zusammensetzung [MLdam(H2O)3] · 2,5 H2O mit M = Mn2+, Co2+, Ni2+; H2L = Bicyclo[2.2.1]hept-5-en-2-endo,3-cis-dicarbonsäure und dam = 2,2′-Dipyridyl, 1,10-Phenanthrolin wird beschrieben. Die Komplexe werden durch quantitative Analysen, IR- und Elektronenspektren sowie Magnetmessungen charakterisiert.Die Ergebnisse der Röntgenkristallstrukturanalyse von [MnLdipy(H2O)3] · 2,5 H2O (1 a) und [CoLdipy(H2O)3] · 2,5 H2O (1 b) zeigen, daß beide Verbindungen isotyp kristallisieren und belegen die oktaedrische Koordination der Metallatome. Das Dicarboxylat-Anion ist mit nur einem O-Atom am Zentralatom gebunden, die zweite Carboxylatgruppe liegt ionisch vor. Je ein O-Atom jeder Carboxylatgruppe geht eine intramolekulare Wasserstoffbrückenbindung mit einem koordinativ gebundenem Wassermolekül ein. Die restlichen Kristallwassermoleküle bilden ein die Packung stabilisierendes Wasserstoffbrückennetz untereinander und mit den Komplexmolekülen.
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  • 76
    ISSN: 0044-2313
    Keywords: Lanthanum niobium selenides ; misfit layer compound ; crystal structure ; electronic properties ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Struktur und elektronische Transporteigenschaften der „Misfit“-Schichtverbindung (LaSe)1,14(NbSe2)2, „LaNb2Se5“.Die neue „Misfit“-Schichtverbindung (LaSe)1,14(NbSe2)2 wurde aus den Elementen bei 1050°C dargestellt und ihre Struktur in mehreren Teilschritten bestimmt. Die Struktur besteht aus einer alternierenden Stapelfolge von [LaSe]- und zwei [NbSe2]-Schichten in c-Richtung. Der „Misfit“ zwischen den zwei verschiedenen Schichten wird entlang der a-Richtung deutlich: a1(LaSe)=6,0191 Å und a2(NbSe2)=3,4372 Å, woraus sich ein Verhältnis von 1,751 ergibt, das 7/4 sehr nahe kommt. Der elektrische Widerstand wurde in Abhängigkeit von der Temperatur gemessen. Die Kristalle zeigen supraleitende Eigenschaften ab 5,3 K.
    Notes: The new misfit layer compound (LaSe)1.14(NbSe2)2 has been synthesized from the elements at 1050- and its structure has been determined by a composite approach. The structure has an alternating stacking sequence of [LaSe] and two [NbSe2] layers along the c direction. The misfit of the two different layers is occurring along the a direction: a1(LaSe)=6.0191 Å and a2(NbSe2)=3.4372 Å therefore yielding a ratio of 1.751 which is very close to 7/4. An investigation of electrical resistivity was done. The crystal shows superconducting properties at 5.3 K.
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  • 77
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 70-72 
    ISSN: 0044-2313
    Keywords: Sodium thioargentate ; cluster ; preparation ; crystal structure ; extended Hückel calculation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NaAg3S2, a Thioargentate Containing the Anionic Cluster [Ag6S4]2-.Dark-red octahedrally shaped crystals of NaAg3S2 could be obtained by the reaction of NaAg(CN)2 and NaCN in a stream of hydrogen sulfide at 630 K. NaAg3S2 crystallizes cubic, a=12.358(1) Å, space group Fd3m, Z=16. The structure was determined from four-circle diffractometer data. NaAg3S2 contains the anionic cluster [Ag6S4]2-. The structure can be traced back to the spinel structure typ. An extended Hückel calculation for the cluster anion, which is considered to be isolated, shows weak bonding silver-silver interactions. NaAg3S2 is diamagnetic at room temperature.
    Notes: Dunkelrote oktaederförmige Kristalle der Verbindung NaAg3S2 wurden bei der Umsetzung von Natriumcyanoargentat mit Natriumcyanid im Schwefelwasserstoffstrom bei 630 K erhalten. NaAg3S2 kristallisiert kubisch, a=12,358(1) Å, Raumgruppe Fd3m, Z=16. Die Struktur wurde über Einkristalle mit Vierkreisdiffraktometerdaten bestimmt. NaAg3S2 enthält als Clusteranion die Baugruppe [Ag6S4]2-. Die Struktur läßt sich auf den Spinelltyp zurückführen. Eine Extended-Hückel-Rechnung für das als isoliert angenommene Clusteranion ergibt schwache bindende Wechselwirkungen zwischen den Silberatomen. NaAg3S2 ist bei Raumtemperatur diamagnetisch.
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  • 78
    ISSN: 0044-2313
    Keywords: Aluminium chloride triammoniate ; tetraammine dichloro aluminium-diammine tetrachloro aluminate ; synthesis ; crystal structure ; IR spectrum ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: AlCl3 · 3NH3  -  a Compound with the Crystal Structure of a Tetraammine Dichloro Aluminium-Diammine Tetrachloro Aluminate: [AlCl2(NH3)4]+[AlCl4(NH3)2]-.AlCl3 · 3 NH3 ≙ [AlCl2(NH3)4]+ [AlCl4(NH3)2]- forms during the reaction of two mole NH3 with AlCl3(NH3) at T ≥ 200°C. Repeated heating and cooling within 48 h between 200°C and 250°C gives a homogeneous product with total uptake of the necessary amount of NH3. Slow sublimation in a vacuum line apparatus at 200°C gives crystals of the triammoniate sufficient for a X-ray structure determination: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm P\bar 1,}\,{\rm Z}\,{\rm = }\,{\rm 2} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}\,{\rm = }\,{\rm 5}{\rm .713(2)}\,{\rm {\AA},}} \hfill & {{\rm b}\,{\rm = }\,{\rm 6}{\rm .512}\,{\rm {\AA}},} \hfill & {{\rm c}\,{\rm = }\,{\rm 9}{\rm .499(3)}\,{\rm {\AA}}} \hfill \\ {{\rm \alpha }\,{\rm = }\,8{\rm 6}{\rm .39(3)}^ \circ,} \hfill & {{\rm \beta }\,{\rm = }\,{\rm 87}{\rm .13(3)}^ \circ } \hfill & {{\rm \gamma }\,{\rm = }\,{\rm 84}{\rm .82(3)}^ \circ } \hfill \\ \end{array} $$\end{document}The compound contains elongated [AlCl2(NH3)4]+ octahedra and compressed [AlCl4(NH3)2]- octahedra. Besides ionic bonding hydrogen bridge bonds with 3.369 Å ≤ d(N - H … Cl) ≤ 3.589 Å stabilize the atomic arrangement.
    Notes: AlCl3 · 3NH3 ≙ [AlCl2(NH3)4]+ · [AlCl4(NH3)2]- entsteht bei der Umsetzung von AlCl3(NH3) mit zwei Mol NH3 bei T ≥ 200°C. Wiederholtes Aufheizen und Abkühlen im Temperaturbereich von 200°C bis 250°C führt innerhalb von 48 h zu homogenen Produkten unter vollständiger Aufnahme der vorgegebenen NH3-Menge. Durch langsame Sublimation im Vakuum bei 200°C lassen sich meist stark verwachsene Kristalle des Triammoniakats züchten. Röntgenographisch wurde die Struktur bestimmt: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm P\bar 1,}\,{\rm Z}\,{\rm = }\,{\rm 2} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {{\rm a}\,{\rm = }\,{\rm 5,713(2)}\,{\rm {\AA},}} \hfill & {{\rm b}\,{\rm = }\,{\rm 6,512}\,{\rm {\AA}},} \hfill & {{\rm c}\,{\rm = }\,{\rm 9,499(3)}\,{\rm {\AA}}} \hfill \\ {{\rm \alpha }\,{\rm = }\,8{\rm 6,39(3)}^ \circ,} \hfill & {{\rm \beta }\,{\rm = }\,{\rm 87,13(3)}^ \circ } \hfill & {{\rm \gamma }\,{\rm = }\,{\rm 84,82(3)}^ \circ } \hfill \\ \end{array} $$\end{document} R/Rw = 5,5/7,0 bei Z(Fo2 〉 3σ Fo2) = 1106 und Z(Var.) = 67Die Verbindung ist aus elongierten [AlCl2(NH3)4]′ -und gestauchten [AlCl4(NH3)2]--Oktaedern aufgebaut. Neben ionogenen Bindungsanteilen ist die Atomanordnung durch H-Brückenbindungen mit 3,369 Å ≤d(N—H … Cl) ≤ 3,589 Å stabilisiert.
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  • 79
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    Zeitschrift für anorganische Chemie 619 (1993), S. 318-320 
    ISSN: 0044-2313
    Keywords: Indium ; phosphorus ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of [{(tBu2P)2InCl}2]The reaction of InCl3 with tBu2PSiMe3 leads to [{(tBu2P)2InCl}2] (1). 1 crystallizes in the space group P21/c. The lattice constants (at 216 K) are: a = 945.9(5) pm, b = 1 604.1(9) pm, c = 1 636.8(8) pm, β = 100.55(4)°. 1 contains a planar In2P2 ring. Each In atom is coordinated by two bridging tBu2P groups, a terminal tBu2P group and a terminal Cl atom. The coordination geometry of the In atoms is roughly tetrahedral.
    Notes: InCl3 reagiert mit tBu2PSiMe3 in Toluol als Lösungsmittel zu [{(tBu2P)2InCl}2] (1). 1 kristallisiert in der Raumgruppe P21/c mit den Gitterkonstanten (bei 216 K): a = 945,9(5) pm, b = 1 604,1(9) pm, c = 1 636,8(8) pm, β = 100,55(4)°. Nach der Kristallstrukturanalyse enthält 1 einen planaren In2P2-Ring. Die In-Atome sind jeweils verzerrt tetraedrisch koordiniert von zwei verbrückenden tBu2P-Gruppen, einer terminalen tBu2P-Gruppe und einem terminalen Chloratom.
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  • 80
    ISSN: 0044-2313
    Keywords: Lanthanoid nickel carbides, Ln4Ni2C5 ; crystal structure ; magnetic susceptibility ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und Kristallstruktur der isotypen Carbide Ln4Ni2C5 (Ln = Er, Tm, Yb und Lu)Die Titelverbindungen wurden durch Reaktion der Elemente in einer Lithiumschmelze hergestellt und ihre Kristallstruktur aus Einkristalldaten der Ytterbiumverbindung bestimmt. Sie kristallisieren rhombisch, Pmm2, a = 352,88(6) pm, b = 1 143,0(3) pm, c = 366,16(6) pm, Z = 1, R = 0,020 für 1 261 Strukturfaktoren und 29 variable Parameter. Die Struktur enthält eine Abfolge von Schichten, wie sie von CeNiC2 und ScC (NaCl Typ) bekannt sind. Dementsprechend enthält sie C2-Paare mit einem C—C-Abstand von 138(1) pm und isolierte Kohlenstoffatome. Zusammen mit den Nickelatomen bilden die C2-Paare eindimensional-unendliche Verbände der Zusammensetzung [Ni2C4]n. Das fünfte Kohlenstoffatom ist oktaedrisch von Ytterbiumatomen umgeben. Daher kann die Verbindung mit (formalen) Oxidationszahlen gemäß der Formel (Yb3+)4[Ni2C48-]C4- beschrieben werden. Die magnetischen Suszeptibilitäten von Yb4Ni2C5 zeigen Curie-Weiss-Verhalten mit einem magnetischen Moment von μexp = 4,44 μB in guter Übereinstimmung mit dem für Yb3+ zu erwartenden Wert von μeff = 4,53 μB.
    Notes: The title compounds were prepared from the elemental components in a lithium flux. Their crystal structure was determined for the ytterbium compound from single-crystal X-ray data. It is orthorhombic, Pmm2, a = 352.88(6) pm, b = 1 143.0(3) pm, c = 366.16(6) pm, Z = 1, R = 0.020 for 1 261 structure factors and 29 variable parameters. The structure may be viewed as an intergrowth of slabs consisting of the CeNiC2 and the ScC (NaCl type) structures. It thus contains C2 pairs with a C—C distance of 138(1) pm and isolated carbon atoms. Together with the nickel atoms the C2 pairs form one-dimensionally infinite building elements [Ni2C4]n. The fifth carbon atom is octahedrally coordinated by ytterbium atoms. Accordingly the compound may be rationalized to a first approximation with the formula (Yb3+)4[Ni2C48-]C4-. Yb4Ni2C5 shows Curie-Weiss behaviour with a magnetic moment of μexp = 4.44 μB per ytterbium atom in good agreement with the theoretical moment of μeff = 4.53 μB for Yb3+.
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  • 81
    Electronic Resource
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 343-346 
    ISSN: 0044-2313
    Keywords: Sodium ; barium ; nickel ; oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The First Alkalinc Alkaline Earth Oxoniccolate(II,III): NaBa2Ni22+Ni3+O6Single crystals of NaBa2Ni22+Ni3+O6 were prepared by solid state reaction. X-ray investigations led to orthorhombic symmetry, space group D2h23-Fmmm; a = 8.310; b = 11.220; c = 14.397 Å; Z = 8. Na+ is coordinated by six O2- in form of a trigonal prism and the two Ba2+ point positions show different coordination numbers C.N. = 6 + 4 and 8. The Ni2+ /Ni3+ ions are in square planar polygons, six of them are forming a so far unknown closed macro polyhedra.
    Notes: Einkristalle von NaBa2Ni22+Ni3+O6 wurden durch Feststoffreaktionen erhalten. Es kristallisiert orthorhombisch, Raumgruppe D2h23-Fmmm; mit a = 8,310; b = 11,220; c = 14,397 Å; Z = 8. Na+ ist von O2- in Form trigonaler Prismen sechsfach koordiniert und Ba2+ zeigt zwei Punktlagen mit Koordinationszahlen von C.N. = 6 + 4 und 8. Die Ni2+ /Ni3+-Ionen sind quadratisch planar koordiniert, sechs NiO4-Polygone verknüpfen zu einem für Nickel zum ersten Male beobachteten geschlossenen Riesenpolyeder.
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  • 82
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 608-612 
    ISSN: 0044-2313
    Keywords: Irondiiodide complexes ; irontriiodide complexes ; tetramethylurea ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complexes of FeI2 and FeI3 with Tetramethylurea[FeI2(OC(NMe2)2)2] (1, [Fe2I4(OC(NMe2)2)2] (2), and [FeI3(OC(NMe2)2] (3) were prepared by the reaction of FeI2 and FeI2/iodine, respectively, with tetramethylurea.The structures of 1 and 3 were determined from single crystal X-ray diffraction data. 1 crystallizes in the triclinic space group P1, with a = 809.9(1), b = 923.2(1), c = 1 374.6(1) pm, α = 106.80(1), β = 90.47(1), γ = 101.55(1)°; Z = 2; R = 0.045., 3: monoclinic, P21/c, a = 1 311.4(1), b = 783.3(1), c = 1 409.1(1) pm, β = 97.36(1)°; Z = 4; R = 0.047.1 and 3 are isolated neutral complexes with distorted tetrahedral coordination of iron. 3 is the first FeI3-complex with an O-donor ligand.The IR-spectra exhibit strong shifts of n̈C = O and n̈asC - N of tetramethylurea especially on coordinating to FeI3.
    Notes: [FeI2(OC(NMe2)2)2] (1), [Fe2I4(OC(NMe2)2)2] (2) und [FeI3(OC(NMe2)2] (3) werden durch Reaktion von FeI2 bzw. FeI2 und Iod mit Tetramethylharnstoff dargestellt.Die Kristallstrukturen von 1 und 3 wurden durch Röntgenbeugung bestimmt. 1 kristallisiert triklin, P1, mit a = 809,9(1), b = 923,2(1), c = 1 374,6(1) pm, α = 106,80(1), β = 90,47(1), γ = 101,55(1)°; Z = 2; R = 0,045. 3: monoklin, P21/c, a = 1 311,4(1), b = 783,3(1), c = 1 409,1(1) pm, β = 97,36(1)°; Z = 4; R = 0,047.1 und 3 enthalten isolierte neutrale Komplexe mit verzerrt tetraedrischer Koordination von Eisen. 3 ist der erste FeI3-Komplex mit einem O-Donorliganden. Die Schwingungsspektren zeigen starke Verschiebungen von n̈C = O und n̈asC - N für Tetramethylharnstoff besonders bei der Koordination an FeI3.
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  • 83
    ISSN: 0044-2313
    Keywords: Multinuclear phosphido-bridged Ag-, Zn- and Cd-Complexes ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Phosphido-bridged Multinuclear Complexes of Ag, Cd and Zn. The Crystal Structures of [Ag4(PPh2)4(PMe3)4], [Ag6(PPh2)6(PtBu3)2] and [M4Cl4(PPh2)4(PnPr3)2] (M = Zn, Cd)AgCl reacts with Ph2PSiMe3 in the presence of a tertiary Phosphine PMe3 or PtBu3 to form the multinuclear complexes [Ag4(PPh2)4(PMe3)4] (1) and [Ag6(PPh2)6(PtBu3)2] (2). In analogy to that MCl2 reacts with Ph2PSiMe3 in the presence of PnPr3 to form the two multinuclear complexes [M4Cl4(PPh2)4(PnPr3)2] (M = Zn (3), Cd (4)). The structures were characterized by X-ray single crystal structure analysis (1: space group Pna21 (Nr. 33), Z = 4, a = 1 313.8(11) pm, b = 1 511.1(6) pm, c = 4 126.0(18) pm, 2: space group P-1 (Nr. 2), Z = 2, a = 1 559.0(4) pm, b = 1 885.9(7) pm, c = 2 112.4(8) pm, α = 104.93(3)°, β = 94.48(3)°, γ = 104.41(3)°; 3: space group C2/c (Nr. 15), Z = 4, a = 2 228.6(6) pm, b = 1 847.6(6) pm, c = 1 827.3(6) pm, β = 110.86(2); 4: space group C2/c (Nr. 15), Z = 4, a = 1 894.2(9) pm, b = 1 867.9(7) pm, c = 2 264.8(6) pm, β = 111.77(3)°). 3 and 4 may be considered as intermediates on the route towards polymeric [M(PPh2)2]n (M = Zn, Cd).
    Notes: AgCl reagiert mit Ph2PSiMe3 in Gegenwart der tertiären Phosphane PMe3 und PtBu3 unter Bildung der mehrkernigen Komplexe [Ag4(PPh2)4(PMe3)4] (1) und [Ag6(PPh2)6(PtBu3)2] (2). Analog dazu reagiert MCl2 mit Ph2PSiMe3 und PnPr3 zu den mehrkernigen Komplexen [M4Cl4(PPh2)4(PnPr3)2] (M = Zn 3), Cd (4)). Die Struktur der Komplexe konnte durch Kristallstrukturanalysen aufgeklärt werden (1: Raumgruppe Pna21 (Nr. 33), Z = 4, a = 1 313,8(11) pm, b = 1 511,1(6) pm, c = 4 126,0(18) pm, 2: Raumgruppe P1 (Nr. 2), Z = 2, a = 1 559,0(4) pm, b = 1 885,9(7) pm, c = 2 112,4(8) pm, α = 104,93(3)°, β = 94,48(3)°, γ = 104,41(3)°; 3: Raumgruppe C2/c (Nr. 15), Z = 4, a = 2 228,6(6) pm, b = 1 847,6(6) pm, c = 1 827,3(6) pm, β = 110,86(2); 4: Raumgruppe C2/c (Nr. 15), Z = 4, a = 1 894,2(9) pm, b = 1 867,9(7) pm, c = 2 264,8(6) pm, β = 111,77(3) 3 und 4 können als Vorstufen auf dem Weg zur Bildung von polymerem [M(PPh2)2]n (M = Zn, Cd) angesehen werden.
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  • 84
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    Zeitschrift für anorganische Chemie 619 (1993), S. 849-852 
    ISSN: 0044-2313
    Keywords: Bis(pyridin)bis(trifluoromethyl)zinc ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of Bis(pyridine)bis(trifluoromethyl)zincBis(pyridin)bis(trifluoromethyl)zinc 1 has been isolated and characterized by means of single-crystal X-ray diffraction techniques. The title compound represents the first structure determination of a fully fluorinated alkylzinc compound (monoclinic, space group P21/c, Z = 4, a = 8.856(3), b = 18.158(3), c = 8.979(3) Å, β = 98.14(2)°, R = 0.054, Rw = 0.035). The zinc atom is in a distorted tetrahedral environment. The molecular structure of [ClZn(CCl2CF3) η2O]2 2 was solved, but is not included in a structural comparison due to crystallographic disorder.
    Notes: Der Pyridin-Komplex 1 von Bis(trifluoromethyl)zink wurde durch Einkristall-Röntgenstrukturanalyse charakterisiert. Die Titelverbindung repräsentiert die erste Struktur eines vollfluorierten Zinkalkyls (monoklin, Raumgruppe P21/c, Z = 4, a = 8,856(3), b = 18,158(3), c = 8,979(3) Å, β = 98,14(2)°, R = 0,054, Rw = 0,035). Das Zinkatom ist verzerrt tetraedrisch koordiniert. Die Kristall- und Molekülstruktur der zweikernigen Zinkverbindung [ClZn(CCl2CF3) η2O]2 2 wurde bestimmt, kann aber wegen kristallographischer Fehlordnung nicht einem Strukturvergleich unterzogen werden.
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  • 85
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 859-864 
    ISSN: 0044-2313
    Keywords: 2,2-Bis(diisopropoxyphosphonyl)propyl methyltin dibromide ; synthesis ; crystal structure ; n.m.r. data ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular Structure of 2,2-Bis(diisopropoxyphosphonyl)propyl Methyltin DibromideBy methylation of Me3SnCH2CH[P(O)(OPr-i)2]2 with NaH/MeI Me3SnCH2C(Me)[P(O)(OPr-i)2]2 (1) is obtained, which is converted by bromine into the dibromide MeBr2SnCH2C(Me)[P(O)(OPr-i)2]2 (2). An X-ray crystal structure analysis shows 2 to be monomeric. The tin atom is situated in the centre of a distorted octahedron, in which the functional substituent is intramolecular coordinated as tridentate ligand in a facial mode. The two organo groups are arranged in trans-position (C—Sn—C 155.1°), whereas the oxygen and bromine atoms are orientated cis to each other. The six-membered ring of the bicyclic molecular fragment of 2 which results from the coordination of the functional organo group to the tin atom shows a boat-conformation, whereas the two five-membered rings exist in twist-conformations. Multinuclear n.m.r. and i.r. data show that 2 retains its solid state structure also in nonpolar solvents.
    Notes: Durch Methylierung von Me3SnCH2CH[P(O)(OPr-i)2]2 mittels NaH/MeI erhält man Me3SnCH2C(Me)[P(O)(OPr-i)2]2 (1), das mit Brom in das Dibromid MeBr2SnCH2C(Me)[P(O)(OPr-i)2]2 (2) überführt wird. Nach der Röntgenkristallstrukturanalyse ist 2 im Festkörper monomer. Das Zinnatom befindet sich im Zentrum eines verzerrten Oktaeders, in dem der funktionelle Substituent intramolekular als tridentater Ligand in facialer Anordnung koordiniert ist. Die beiden Organoreste sind trans-ständig angeordnet (C—Sn—C 155,1°), während sich die Sauerstoff- und Bromatome in cis-Anordnung zueinander befinden. Der Sechsring des aus der Koordination des funktionellen Organorestes am Zinnatom resultierenden bicyclischen Molekülfragmentes von 2 weist Wannenkonformation auf, während die beiden Fünfringe in Twist-Konformationen vorliegen. Multikern-NMR- und IR-Daten belegen, daß 2 seine Festkörperstruktur auch in unpolaren Lösungsmitteln beibehält.
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  • 86
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1419-1425 
    ISSN: 0044-2313
    Keywords: Lithium permanganate, Li[MnO4] ; preparation ; crystal structure ; neutron powder data ; MAPLE calculation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Coordination Number 4 or 6 for Lithium?: The Crystal Structure of Lithium Permanganate, Li[MnO4]Waterless 7Li[MnO4] was obtained by dehydration of 7Li[MnO4] · 3 D2O at 60°C above P4O10 in vacuum as violet powder.The structure determination by neutron diffraction measurements via pulsed polychromatic neutron source [time-of-flight powder diffractometer; profile-R-value = 2.1%, Bragg-R-value = 7.4%] confirms the space group Cmcm with a = 551.402(8), b = 839.754(15), c = 635.911(10) pm (Z = 4); parameters see text. The crystal structure of Li[MnO4] corresponds to the CrVO4-type with coordination number 6 for lithium and 4 for manganese.The Madelung Part of Lattice Energie, MAPLE, the Effective Coordination Numbers, ECoN and the charge distribution were calculated and discussed.
    Notes: Durch Trocknung von 7Li[MnO4] · 3 D2O bei 60°C über P4O10 im Vakuum wurde wasserfreies 7Li[MnO4] als violettes Pulver erhalten.Die Strukturaufklärung mittels Neutronenbeugungsmessungen im gepulsten polychromatischen Neutronenstrahl [Flugzeitdiffraktometer; Profil-R-Wert = 2,1%, Bragg-R-Wert = 7,4%] belegt die Raumgruppe Cmcm mit a = 551,402(8), b = 839,754(15), c = 635,911(10)pm (Z = 4); Parameter siehe Text. Die Kristallstruktur von Li[MnO4] entspricht dem CrVO4-Typ mit der Koordinationszahl 6 für Lithium und 4 für Mangan.Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN und die Ladungsverteilung wurden berechnet und diskutiert.
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  • 87
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1426-1430 
    ISSN: 0044-2313
    Keywords: Manganese fluorides ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Crystal Structure of MnF3 and MnPtF6Single crystal investigations of MnF3 (rubyred) confirmed the crystal structure based on powder data [2]: monoclinic, space group C 2/c-C2h6 (No. 15) with a = 892.02 pm, b = 504.72 pm, c = 1 347.48 pm, β = 92.64° with Z = 12.The corresponding determination of the crystal structure of MnPtF6, yellow, confirmed the unit cell [3] with a = 510.47 pm, c = 1 421.0 pm and γ = 120°, Z = 3 space group R 3-C3i2 (No. 148).For both compounds detailed parameters respectively interatomic distances have been obtained.
    Notes: Einkristalluntersuchungen an MnF3 (rubinrot) bestätigen den aus Pulverdaten [2] abgeleiteten Strukturvorschlag: monoklin, Raumgruppe C 2/c-C2h6 (Nr. 15) mit a = 892,02 pm, b = 504,72 pm, c = 1 347,48 pm, β = 92,64° mit Z = 12 (Vierkreisdiffraktometerdaten).Entsprechende Einkristalluntersuchungen an MnPtF6, hellgelb, bestätigen auch hier die Abmessungen der Elementarzelle [3] mit a = 510,47 pm, c = 1 421,0 pm und γ = 120°, Z = 3 in der Raumgruppe R °3-C3i2 (Nr. 148). Für beide Verbindungen konnten damit genaue Parameter bzw. interatomare Abstände ermittelt werden.
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  • 88
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1446-1454 
    ISSN: 0044-2313
    Keywords: Silver bismuthate ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ag3BiO3 and Ag5BiO4,the first Silver Oxobismuthates(III)Applying high oxygen pressures (100 MPa) Ag3BiO3 and Ag5BiO4 were prepared for the first time by reacting the binary components Ag2O and Bi2O3 at temperatures between 770 and 800 K. Single crystals of both compounds were grown hydrothermally from Ag2O and Bi2O3 at 620 K and at oxygen pressures of 10 MPa. The crystal structure determination (Ag3BiO3: I41, a = 14.1924(1), c = 8.7997(1) Å, Z = 16, 1 729 diffractometer data, Rw = 0.057; Ag5BiO4: P21/n, a = 5.855(1), b = 8.984(1), c = 12.457(1) Å, β = 91.49(1)Å, Z = 4, 2716 diffractometer data, Rw = 0.036) shows that in Ag5BiO4 bismuth approximately has a square pyramidal coordination by five oxygen atoms. Two such pyramids share an edge thus forming ‘isolated’ Bi2O810- anions. In Ag3BiO3 the same groups are linked by the terminal oxygen atoms to form a three dimensional network. In both structures the cation arrangements form variants of the Laves-phases MgCu2 with silver occupying the copper positions. The Mg positions are ordered occupied by bismuth and silver.
    Notes: Ag3BiO3 und Ag5BiO4 wurden durch Festkörperreaktion aus den binären Komponenten Ag2O und Bi2O3 bei Temperaturen zwischen 770 und 800 K und Sauerstoffdrücken von 100 MPa erstmals dargestellt. Einkristalle von beiden Verbindungen konnten durch Hydrothermalreaktion zwischen Ag2O und Bi2O3 bei 620 K unter einem Sauerstoffdruck von 10 MPa dargestellt werden. Nach den Ergebnissen der Röntgenstrukturanalyse (Ag3BiO3: I41, a = 14,1924(1), c = 8,7997(1) Å, Z = 16, 1 729 Diffraktometerdaten, Rw = 0,057; Ag5BiO4: P21/n, a = 5,855(1), b = 8,984(1), c = 12,457(1) Å, β = 91,49(1)Å, Z = 4, 2716 Diffraktometerdaten, Rw = 0,036) liegt in Ag5BiO4 eine transständige Verknüpfung von quadratisch-pyramidal mit Sauerstoff koordinierten BiO5-Baueinheiten zu dimeren, ‘isolierten’, Bi2O810--Gruppen vor. In Ag3BiO3 findet man die gleichen Bi2O8-Baugruppen, die hier jedoch dreidimensional über die terminalen Sauerstoffatome verknüpft sind. In beiden Verbindungen sind die Kationen analog zur Laves-Phase MgCu2 angeordnet mit gemischter Besetzung der Mg-Position durch Silber und Bismut sowie Besetzung der Cu-Positionen ausschließlich durch Silber.
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  • 89
    ISSN: 0044-2313
    Keywords: Disulfonyl amines ; silver(I) 1,1,3,3-tetraoxo-1,3,2-benzodithiazolide ; aqua(1,1,3,3-tetraoxo-1,3,2-benzodithiazolido)silver(I) ; crystal structure ; thermal analysis ; calorimetry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polysulfonyl Amines. XLII. An Aquasilver(I) Complex with an Ag(m̈-H2O)2Ag Structural Unit: Characterization of Aqua(1,1,3,3-tetraoxo-1,3,2-benzodithiazolido)silver(I) by X-Ray Diffractometry and Thermal AnalysisThe title compound C6H4(SO2)2NAg · H2O, where C6H4(SO2)2Nº is the anion of 1,2-benzenedisulfonimide, crystallizes in the monoclinic space group C2/m with (at -95°C) a = 1 129,7(3), b = 1 196.1(3), c = 810.7(2) pm, β = 124.25(2)°, V = 0.9055 nm3, Z = 4, Dx = 2.524 Mg m-3. The crystal packing consists of [Ag(m̈-H2O)2Ag{m̈-C6H4(SO2)2N}2]n bands with crystallographic mirror symmetry, associated into layers by H-bonds with O(W) - O(S) 289.7 pm. The Ag(m̈-H2O)2Ag moiety forms a planar four-membered ring with Ag—O(W)—Ag 97.3°, O(W)—Ag—O(W) 82.7° and Ag°Ag 372.1 pm. In the Ag{C6H4(SO2)2N}2Ag′ unit, the anions act as tridentate (N, 1-O, 3-O)-ligands: One is N-bonded to Ag and O,O-chelated to Ag′, the other N-bonded to Ag′ and O,O-chelated to Ag. The silver atoms are (O4N)-pentacoordinate, with nitrogen in the apical position of a distorted square pyramid [Ag—N 223.6, Ag—O(W) 247.8, Ag—O(S) 259.4 pm]. The thermochemical behaviour of the hydrate was investigated by thermal analysis and calorimetry. Water is only released at temperatures above 220°C. The dehydration enthalpy at 298 K is + 13.9 kJ mol-1.
    Notes: Die Titelverbindung C6H4(SO2)2NAg · H2O, mit C6H4(SO2)2N- = Anion des 1,2-Benzoldisulfonsäureimids, kristallisiert in der monoklinen Raumgruppe C2/m mit (bei -95°C) a = 1 129,7(3), b = 1 196,1(3), c = 810,7(2) pm, β = 124,25(2)°, V = 0,9055 nm3, Z = 4, Dx = 2,524 Mg m-3. Die Kristallpackung besteht aus Strängen des Typs [Ag(m̈-H2O)2Ag{m̈-C6H4(SO2)2N}2]n mit kristallographischer Spiegelsymmetrie, die über H-Brücken mit O(W)…O(S) 289,7 pm zu Schichten assoziiert sind. Die Ag(m̈—H2O)2Ag-Einheit bildet einen planaren Vierring mit Ag - O(W) - Ag 97,3°, O(W) - Ag - O(W) 82,7° und Ag…Ag 372,1 pm. In der Ag{m̈—C6H4(SO2)2N}2Ag′-Einheit wirken die Anionen als dreizähnige (N, 1-O, 3-O)-Liganden, und zwar das eine als N-Donor gegenüber Ag und als O,O-Chelatligand gegenüber Ag′, das andere umgekehrt als N-Donor gegenüber Ag′ und als O,O-Chelatligand gegenüber Ag. Die Silberatome sind (O4N)-pentakoordiniert mit dem Stickstoffatom am Scheitelpunkt einer verzerrten quadratischen Pyramide [Ag—N 223,6, Ag—O(W) 247,8, Ag—O(S) 259,4 pm]. Das thermochemische Verhalten des Hydrats wurde mit thermoanalytischen und kalorimetrischen Methoden untersucht. Das Wasser wird erst bei Temperaturen oberhalb 220°C abgegeben. Die Dehydratationsenthalpie bei 298 K beträgt + 13,9 kJ mol-1.
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  • 90
    ISSN: 0044-2313
    Keywords: Tris[(trialkylphosphine)gold(I)]oxonium salts ; tris[(triphenylphosphine)gold(I)]sulfonium salts ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Tris[(trialkylphosphine)gold(I)]oxonium Tetrafluoroborates and Tris[(triphenylphosphine)gold(I)]sulfonium Tetrafluoroborate[Et3PAu]+BF4-, obtained from Et3PAuCl and AgBF4 in tetrahydrofuran, reacts with KOH (molar ratio 3:1) to give the oxonium salt [(Et3P)Au]3O+BF4- (1). The homologous [t(Bu3P)Au]3O+BF4- (2) is generated similarly from tBu3PAuCl and Ag2O in the presence of NaBF4 in THF. The composition and identity of these two first tris[(trialkylphosphine)gold(I)]oxonium salts have been confirmed by analytical and spectroscopic data. The compounds are useful aurating agents. From the corresponding triphenylphosphine complex and (Me3Si)2S quantitative yields of the sulfonium salt [(Ph3P)Au]3S+BF4- (3) are obtained. Its crystal structure features monomeric cations, and in these small Au—S—Au angles indicate significant metal-metal bonding.
    Notes: Das durch Umsetzung von Et3PAuCl mit AgBF4 entstehende [Et3PAu]+BF4- ergibt mit KOH (Molverhältnis 3:1) in Tetrahydrofuran das Oxonium-Salz [(Et3P)Au]3O+BF4- (1). Ähnlich entsteht aus Bu3PAuCl und Ag2O in Gegenwart von NaBF4 in THF das homologe [(tBu3P)Au]3O+BF4- (2). Diese beiden ersten Tris[(trialkylphosphan)gold(I)]oxonium-Salze wurden durch analytische und spektroskopische Daten in ihrer Zusammensetzung und Identität gesichert. Sie sind wichtige Aurierungsreagentien. Aus dem zugehörigen Triphenylphosphan-Komplex entsteht mit (Me3Si)2S quantitativ das Sulfonium-Salz [(Ph3P)Au]3S+BF4- (3). Seine Kristallstrukturanalyse zeigt monomere Trigoldsulfonium-Kationen mit steiler SAu3-Pyramide. Kurze Au … Au-Abstände und kleine Au—S—Au-Winkel deuten signifikante Au  -  Au-Wechselwirkungen an.
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  • 91
    ISSN: 0044-2313
    Keywords: monoplatinum nonagold cluster cluster ; monoplatinum dicobalt cluster ; monoplatinum tetragold cluster ; [(Ph3PAu)6(AuCl)3Pt(CO)] ; [(dppe)PtCo2(CO)7] ; [(Ph3PAu)4Pt(dppe)](PF6)2 ; synthesis ; photolysis of azido complexes ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cluster Synthesis by Photolysis of Azido Complexes of Platinum and Gold. Syntheses and Crystal Structures of [(Ph3PAu)6(AuCl)3Pt(CO)], [(dppe)PtCo2(CO)7] and [(Ph3PAu)4Pt(dppe)](PF6)2Photolysis of a mixture of Ph3PAuN3, Ph3PAuCl and (Ph3P)2Pt(N3)2 in THF yields after chromatographic separation with CH2Cl2/EtOH as eluens the cluster [(Ph3PAu)6(AuCl)3Pt(CO)] (1). It crystallizes in the triclinic space group P1 with the lattice parameters a = 2 139.3(4), b = 2 457.1(4), c = 2 561.9(1) pm, α = 79.74(9)°, β = 80.06(6)°, γ = 66.05(5)°, Z = 4. The nine gold atoms form a fragment of an icosahedron with the platinum atom in its center. Upon photolysis of (dppe)Pt(N3)2 with Co2(CO)8 in THF one m̈2-CO ligand of the cobalt carbonyl is substituted by a (dppe)Pt group. The resulting cluster [(dppe)PtCo2(CO)7] (2) crystallizes monoclinically in the space group P21/n with a = 1 303.9(3), b = 1 768.1(8), c = 1 461.4(4) pm, β = 102.81(1)°, Z = 4. Photolysis of 2 with excess Ph3PAuN3 affords the clusters [(Ph3PAu)4Pt(dppe)]2+ (3), and [(Ph3PAu)6AuCo2(CO)6]+. 3 crystallizes with PF6- as counterions in the triclinic space group P1 with a = 1 369.1(4), b = 1 505.0(4), c = 2 773.0(8) pm, α = 84.74(1)°, β = 87.37(2)°, γ = 65.94(2)°, Z = 2. The Au4Pt skeleton of 3 forms a trigonal bipyramid with the platinum atom in equatorial position.
    Notes: Die Photolyse einer Mischung von Ph3PAuN3, Ph3PAuCl und (Ph3P)2Pt(N3)2 in THF ergibt nach chromatographischer Reinigung mit CH2Cl2/EtOH als Eluens den Cluster [(Ph3PAu)6(AuCl)3Pt(CO)] (1). Er kristallisiert triklin in der Raumgruppe P1 mit den Gitterkonstanten: a = 2 139,3(4), b = 2 457,1(4), c = 2 561,9(1) pm, α = 79,74(9)°, β = 80,06(6)°, γ = 66,05(5)°, Z = 4. Die neun Goldatome bilden ein Ikosaederfragment, in dessen Zentrum sich das Pt-Atom befindet. Bei der Photolyse einer Mischung von (dppe)Pt(N3)2 mit Co2(CO)8 in THF wird ein m̈2-CO-Ligand des Cobaltcarbonyls durch eine (dppe)Pt-Gruppe substituiert. Der resultierende Cluster [(dppe)PtCo2(CO)7] (2) kristallisiert monoklin mit der Raumgruppe P21/n und a = 1 303,9(3), b = 1 768,1(8), c = 1 461,4(4) pm, β = 102,81(1)°, Z = 4. Die Photolyse von 2 mit überschüssigem Ph3PAuN3 führt auf die Cluster [(Ph3PAu)4Pt(dppe)]2+ (3) und [(Ph3PAu)6AuCo2(CO)6]+. 3 kristallisiert als PF6- -Salz in der triklinen Raumgruppe P1 mit a = 1 369,1(4), b = 1 505,0(4), c = 2 773,0(8) pm, α = 84,74(1)°, β = 87,37(2)°, γ = 65,94(2)°, Z = 2. Das Au4Pt-Gerüst von 3 bildet eine trigonale Bipyramide mit dem Pt-Atom in äquatorialer Position.
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  • 92
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1603-1608 
    ISSN: 0044-2313
    Keywords: Lanthanum acetate ; ammonium lanthanum acetate ; synthesis ; crystal structure ; thermal behaviour ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anhydrous Lanthanum Acetate, La(CH3COO)3, and its Precursor, ·NH4)3[La(CH3COO)6] · 1/2 H2O: Synthesis, Structures, Thermal BehaviourSingle crystals of (NH4)3[La(CH3COO)6] · ½ H2O are obtained by refluxing La2O3in (CH3COO)3 · 1.5 H2O with an excess of NH4CH3COO in methanol. The crystal structure (trigonal, R3, Z = 6, a = 1 365.0(3) pm, c = 2 360(1) pm, R = 0.088, Rw = 0.061 exhibits the coordination number of nine for La3+, which is surrounded by three chelating-type bidentate and three unidentate acetate groups. Characteristic are monomeric units of [La(CH3COO)6]3- which are connected to a three-dimensional network by hydrogen bonds with the NH4+ ions. Thermal decomposition consists of four steps with La(CH3COO)3, La2(CO3)3 and La2O2CO3 as intermediates and La2O3 as the final Product. Single crystals of La(CH3COO)3 are obtained from La2O3 in a melt of NH4CH3COO (molar ratio 1:12) in a sealed glass ampoule. The crystal structure (trigonal, R3, Z = 18, a = 2 203.0(5) pm; c = 987.1(3) pm, R = 0.027, Rw = 0.023) shows the coordination number of ten for La3+. These are three-dimensionally connected by oxygen atoms of the acetate groups with two tetradentate double-bridging and one Z,Z-type-bridging bidentate acetate group.
    Notes: (NH4)3[La(CH3COO)6] · 1/2 H2O erhält man in Form von Einkristallen durch Erhitzen von La2O3 bzw. La(CH3COO)3 · 1,5 H2O mit einem Überschuß von Ammoniumacetat in Methanol. Die Röntgenstrukturanalyse (trigonal, R3, Z = 6, a = 1 365,0(3) pm, a = 2 360(1) pm, R = 0,088, Rw = 0,061 zeigt, daß La3+ von jeweils drei „chelating-type bidentate“- bzw. „unidentate“-Acetatgruppen umgeben ist (Koordinationszahl neun). Die Kristallstruktur wird von monomeren anionischen Baueinheiten [La(CH3COO)6]3- bestimmt, welche über Wasserstoffbrückenbindungen mit den NH4+-Ionen zu einer dreidimensionalen Struktur verknüpft sind. Der thermische Abbau verläuft in vier Stufen über La(CH3COO)3, La2(CO3)3 und La2O2CO3 zu La2O3. Einkristalle von La(CH3COO)3 erhält man aus einer Schmelze von La2O3 in NH4CH3COO (molares Verhältnis 1:12) in einer abgeschmolzenen Glasampulle. Die Röntgenstrukturanalyse (trigonal, R3, Z = 18, a = 2 203,0(5) pm; c = 987,1(3) pm, R = 0,027, Rw = 0,023) ergibt für La3+ die Koordinationszahl zehn. Die La3+-Ionen sind dreidimensional über die Sauerstoffatome der Acetatgruppen verknüpft, Pro La3+ zwei „tetradentate double-bridging“-Acetatgruppen und eine „Z,Z-type-bridging bidentate“-Acetatgruppe.
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  • 93
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1095-1097 
    ISSN: 0044-2313
    Keywords: Rubidium auride ; caesium auride ; preparation ; single-crystals ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Single-Crystal Growth and Structure Refinement of RbAu and CsAuSingle-crystals of RbAu and CsAu were obtained by the reaction of the alkalimetal azides with gold-powder at 400°C. The structures were determined from X-ray single-crystal diffraktometer data: space group Pm3m, Z = 1; RbAu, a = 4.098(1) Å, R/Rw(w = 1) = 0.011/0.011, N(Fo2) ≥ 3σ(Fo2) = 41 and N(var.) = 4; CsAu, a = 4.258(1) Å, R/Rw(w = 1) = 0.009/0.010, N(Fo2) ≥ 3σ(Fo2) = 34 and N(var.) = 4. Both compounds crystallize in the completely ordered CsCl-type with neglible deviations from the ideal 1:1-composition.
    Notes: Einkristalle von RbAu und CsAu wurden durch Reaktion der Alkalimetallazide mit Goldpulver bei 400°C erhalten. Die Strukturen wurden aus Einkristall-Röntgen-Diffraktometerdaten bestimmt: Raumgruppe Pm3m, Z = 1; RbAu, a = 4,098(1) Å, R/Rw(w = 1) = 0,011/0,011, Z(Fo2) ≥ 3σ(Fo2) = 41 und Z(Var.) = 4; CsAu, a = 4,258(1) Å, R/Rw(w = 1) = 0,009/0,010, Z(Fo2) ≥ 3σ(Fo2) = 34 und Z(Var.) = 4. Beide Verbindungen kristallisieren im vollständig geordneten CsCl-Typ mit vernachlässigbarer Abweichung von der idealen 1:1-Zusammensetzung.
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  • 94
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1713-1716 
    ISSN: 0044-2313
    Keywords: Pottasium ; magnesium ; copper ; vanadium oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of KMgCu4V3O13.Single crystals of KMgCu4V3O13 were prepared by supercooled melts. It crystallizes with monoclinic symmetry space group C2h2-P21/m (Nr. 11), unit cell dimensions: a = 10.7144 Å, b = 6.0282 Å, c = 8.3365 Å, β = 98.075°, Z = 2. The crystal structure is closely related to the BaMg2Cu8O6O26 type. Cu2+ occurs in an unusual trigonal bipyramidal coordination.
    Notes: Einkristalle von KMgCu4V3O13 wurden aus unterkühlten Schmelzen erhalten. Die Verbindung kristallisiert monoklin Raumgruppe C2h2-P21/m (Nr. 11) mit den Zellparametern: a = 10,7144 Å, b = 6,0282 Å, c = 8,3365 Å, β = 98,075°, Z = 2. Die Kristallstruktur ist eng mit dem BaMg2Cu8V6O26-Typ verwandt. Cu2+ kommt in der seltenen trigonal bipyramidalen Koordination vor.
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  • 95
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1755-1758 
    ISSN: 0044-2313
    Keywords: Lead, rare earth, aluminium, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Chemistry of the Lead Lanthanide Oxoaluminates. On Pb2HoAl3O8 and Pb2LuAl3O8.Single crystals of (I) Pb2HoAl3O8 and (II) Pb2LuAl3O8 were prepared by flux technique and investigated by X-ray methods. It crystallizes with cubic symmetry, space group Oh4-P42/n 3 2/m, (I): a = 9.4164(13) Å, (II): a = 9.3486(8) Å, Z = 4. The new structure type shows AlO4 tetrahedra, LnO8 hexagonal bipyramids and one sided coordinated Pb2+ within heterocubane units. The crystal chemical relationships to other lead oxides containing heterocubane Pb4O4 units are discussed.
    Notes: Mit Schmelzmitteltechnik wurden Einkristalle von (I) Pb2HoAl3O8 und (II) Pb2LuAl3O8 dargestellt. Die röntgenographische Untersuchung führte zu kubischer Symmetrie, Raumgruppe Oh4-P42/n 3 2/m, Zellabmessungen (I): a = 9,4164(13) Å, (II): a = 9,3486(8) Å, Z = 4. Der neue Strukturtyp zeigt AlO4-Tetraeder, hexagonale LnO8-Bipyramiden und einseitig koordinierte Pb2+-Ionen in Heterokubaneinheiten. Die kristallchemischen Beziehungen zu anderen Oxiden des Bleis mit Pb4O4-Baugruppen werden diskutiert.
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  • 96
    ISSN: 0044-2313
    Keywords: Di(phthalocyaninato(1-))praseodymium(III)-polyhalides ; crystal structure ; uv-vis-nir spectra ; mir spectra ; resonance Raman spectra ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Properties of Tetragonal α-Di(phthalocyaninato(1-))praseodymium(III)-polyhalides; Crystal Structure of α-[Pr(Pc-)2]Br1.5Brown red di(phthalocyaninato(1-))-praseodym(III)-polyhalides [Pr(Pc-)2]Xy (X = Br, I) of variable composition (1 ≤ y ≤ 2.5) are formed by (electro)chemical oxidation of [Pr(Pc2-)2]-. The thermical decomposition of these polyhalides at 250°C yields partially oxidized, green α-[PrPc-Pc2-]. Due to strong spin-spin coupling of the phthalocyanin-π-radicals only PrIII contributes to the magnetic moment of ca. 3.0 B.M. for all complexes. Green metallic prisms of [Pr(Pc-)2]Br1.5 crystallize in the tetragonal α-modification: space group P4/nnc with a = 19.634(5) Å, c = 6.485(2) Å; Z = 2. In the sandwich complex PrIII is eightfold coordinated by the isoindoline N-atoms of the two staggered (41°), nearly planar Pc-- ligands. The quasi-onedimensional character of the structure along [001] is due to the infinite columns of Pc- ligands. The superperiod along [001] is a consequence of the distribution of the Pr atoms onto two incompletely filled crystallographic positions at a distance of c/2 and the disordered chains of the bromine atoms extending in the same direction. Powder diffractograms of Pr(Pc )2Br2, [Pr(Pc-)2]I2 und [PrPc Pc2-] confirm the tetragonal α-modification of these complexes, too. The content of tribromide correlates with the population of the Pr(2)-site. In the UV-VIS-NTR absorption spectrum of a thin film of Pr(Pc )2Br, the intense bands at 13.9 and 19.5 kK are assigned to the B and Q transition, respectively. The D band at 9. kK is characteristic for isolated dimeric Pc--π-radicals. Due to increasing electron delocalisation as a result of the growing columns the D band is shifted to lower energy appearing successively at 6.05 and 3.3 kK. The mir and resonance Raman (RR) spectra of α-[Pr(Pr-)2]Xy, (X = Br, I) show the well known diagnostic bands for Pc--π-radicals. Thc RR spectrum of the polyiodide is dominated by the overtone progression of the totally symmetric (I-I) stretching vibration of the triiodide at 108cm-1. The FT-Raman spectra are also marked by the totally symmetric stretching vibration of the polyhalides (Br3 : 145cm 1; 13-:105cm-1; I5- 151 cm-1).
    Notes: Braunrote Di(phthalocyaninato(1-))-praseodym(III)-polyhalogenide [Pr(Pc-)2]Xy (X = Br, I) variabler Zusammensetzung (1 ≤ y ≤ 2,5) bilden sich bei der (elektro)chemischen Oxydation von [Pr(Pc2-)2]-. Die thermische Zersetzung der Polyhalogenide bei 250°C liefert partiell oxydiertes, grünes α-[PrPc-Pc2-]. Wegen der starken Spin-Spin-Kopplung der Phthalocyanin-π-Radikale reduziert sich das magnetische Moment für alle Komplexe auf den Beitrag des PrIII-Kations von ca. 3,0 B.M. Grün metallisch glänzende Nadeln von [Pr(Pc-)2]Br1,5 kristallisieren in der tetragonalen α-Modifikation: Raumgruppe P4/nnc mit a = 19,634(5) Å, c = 6,485(2) Å; Z = 2. In dem Sandwich-Komplex ist PrIII von den Isoindol-N-Atomen der beiden fast planaren, um 41° gegeneinander gedrehten Pc--Liganden achtfach-koordiniert. Die stapelförmige Anordnung der Pc--Liganden bedingen den quasi-eindimensionalen Charakter der Struktur längs [001]. Die Überperiode längs [001] ist eine Folge der Verteilung der Pr-Atome auf zwei unvollständig besetzte kristallographische Positionen im Abstand von c/2 und der in gleicher Richtung verlaufenden ungeordneten Ketten der Bromatome. Die Pulverdiffraktogramme von [Pr(Pc-)2]Br2, [Pr(Pc-)2]I2 und [PrPc-Pc2-] bestätigen die tetragonale α-Modifikation auch für diese Komplexe. Der Tribromid-Gehalt korreliert mit der Besetzung der Pr(2)-Lage. Im UV-VIS-NIR-Absorptionsspektrum eines Dünnfilms von [Pr(Pc-)2]Bry wird die intensive Bande bei 13,9 kK dem B-, die bei 19,5 kK dem Q-Übergang zugeordnet. Die für isolierte dimere Pc--π-Radikale charakteristische D-Bande liegt bei 9,1 kK. Sie verschiebt sich mit zunehmender Elektronendelokalisierung aufgrund wachsender Stapel bathochrom, wobei sie sukzessive bei 6,05, dann 3,3 kK auftritt. Die MIR- und Resonanz-Raman(RR)-Spektren von α-[Pr(Pc-)2]Xy, (X = Br, I) zeigen die für Pc--π-Radikale bekannten diagnostischen Banden. Im RR-Spektrum des Polyiodids dominiert die Obertonprogression der totalsymmetrischen (I - I)-Valenzschwingung des Triiodids (108 cm-1). Die FT-Raman-Spektren sind ebenfalls von der totalsymmetrischen Valenzschwingung des Polyhalogenids geprägt (Br3-: 145 cm-1; I3-: 105 cm-1; I5-: 151 cm-1).
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  • 97
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    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1661-1668 
    ISSN: 0044-2313
    Keywords: Rare earth tetrafluoroaurates(III) ; preparation ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tetrafluoroaurates(III) of Lanthanides MF[AuF4]2 (M = Tm, Yb, Lu).Tetrafluoroaurates(III) MF[AuF4]2 with M = Tm, Yb, Lu, all yellow, have been prepared for the first time. From single crystal data they crystallize orthorhombic, space group Pbcn-D2h14 (No. 60) with M = Tm: a = 1 102.92(8) pm, b = 904.38(8) pm, c = 2 164.46(23) pm; M = Yb: a = 1 100.98(12) pm, b = 902.23(8) pm, c = 2 157.36(23) pm; M = Lu: a = 1 099.28(18) pm, b = 900.70(15) pm, c = 2 151.50(46) pm.
    Notes: Neu dargestellt wurden gelbe Tetrafluoroaurate(III) der Lanthaniden MF[AuF4]2 mit M = Tm, Yb, Lu. Nach Einkristalluntersuchungen kristallisieren diese orthorhombisch in der Raumgruppe Pbcn-D2h14 (Nr. 60) mit Z = 12. Im Einzelnen wurden folgende Werte gefunden: Für M = Tm: a = 1 102,92(8) pm, b = 904,38(8) pm, c = 2 164,46(23) pm; M = Yb: a = 1 100,98(12) pm, b = 902,23(8) pm, c = 2 157,36(23) pm; M = Lu: a = 1 099,28(18) pm, b = 900,70(15) pm, c = 2 151,50(46) pm.
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  • 98
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    Zeitschrift für anorganische Chemie 619 (1993), S. 1682-1684 
    ISSN: 0044-2313
    Keywords: Lithium iodide ; DME complex ; synthesis ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Crystal Structure of [Li(DME)2I].LiI can be dissolved at 50°C in toluene/DME (2:1). At - 20°C [Li(DME)2I] (1) was isolated in 75% yield. 1 was characterized by NMR techniques as well as an X-Ray structure determination. 1 crystallizes in the space group C2/c with a = 1 356.9(2), b = 813.2(1), c = 1 259.1(2) pm, and β = 99.74(1)°.
    Notes: LiI kann bei 50°C in Toluol/DME (2:1) in Lösung gebracht werden. Bei - 20°C wird [Li(DME)2I] (1) in 75% Ausbeute isoliert. 1 wurde mittels NMR-Spektroskopie sowie durch eine Röntgenstrukturanalyse charakterisiert. 1 kristallisiert in der Raumgruppe C2/c mit a = 1 356,9(2), b = 813,2(1), c = 1 259,1(2) pm und β = 99,74(1)°.
    Additional Material: 2 Ill.
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  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1738-1742 
    ISSN: 0044-2313
    Keywords: Strontium, osmium, oxide ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Mixed Valenced Oxoosmate(VI, VII): Sr11Os26+Os27+O24.Single crystals of Sr11Os26+Os27+O24 were prepared in closed silver bombs using SrO, osmium and an extend of KO2. It crystallizes with monoclinic symmetry, space group C2h6-I12/a1 a = 11.703; b = 16.058; c = 11.696 Å; β = 90.03°; Z = 4. Sr11Os26+Os27+O24 shows a new crystal structure characterized by a [Sr11O24]26- network and incorporated Os6+ and Os7+ ions. Calculations of the coulombterm of lattice energy shows an orderer distribution of the two oxidation states of osmium.
    Notes: Einkristalle von Sr11Os26+Os27+O24 wurden in geschlossenen Silberbömbchen aus SrO, Osmium und einem überschuß von KO2 erhalten. Diese Substanz kristallisiert monoklin, Raumgruppe C2h6-I12/a1 mit a = 11,703; b = 16,058; c = 11,696 Å; β = 90,03°; Z = 4. Sie zeigt eine neue Kristallstruktur, die durch ein [Sr11O24]26--Gerüst mit eingelagerten Os6+ und Os7+-Ionen ausgezeichnet ist. Berechnungen des Coulombterm der Gitterenergie führen zu einer geordneten Verteilung der zwei Valenzen des Osmiums.
    Additional Material: 3 Ill.
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  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 1897-1904 
    ISSN: 0044-2313
    Keywords: Mesityltrifluoro gallates ; mesitylbromo indates ; syntheses ; crystal structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mesityltrifluoro Gallates. The Crystal Structures of Cs[MesGaF3] and K[MesInBr3]Mes3Ga reacts with GaBr3 in the ratio 1:2 in a commutation reaction to MesGaBr2 (1). 1 can be reacted with KF and CsF in MeCN to K[MesGaF3] (2) and Cs[MesGaF3] (3), respectively. K[MesInBr3] (4) was isolated when MesInBr2 was treated with KF in MeCN. The use of 15-crown-5 was leading to [K(15-crown-5)2][Mes2InBr2] (5) in a substituent exchange reaction. 1-5 were characterized by NMR-, IR- and MS-techniques. The solid state structures of 3 and 4 could be established by X-ray structure determinations. According to these determinations, a layer-type arrangement of the molecules is both structures in common. In the center of the layers, ionic interactions were formed, while the separation of the layers is caused by the bulky mesityl substituents.
    Notes: Mes3Ga reagiert mit GaBr3 im Verhält-nis 1:2 in einer Kommutierungsreaktion zu MesGaBr2 (1). 1 kann mit KF bzw. CsF in MeCN zu K[MesGaF3] (2) bzw. Cs[MesGaF3] (3) umgesetzt werden. Dagegen konnte bei der Reaktion von MesInBr2 mit KF in MeCN nur K[MesInBr3] (4) isoliert werden. Der Einsatz von 15-Krone-5 führt nach einer Substituentenaustauschreaktion zu [K(15-Krone-5)2][Mes2InBr2] (5). 1-5 wurden mittels NMR- und IR-Spektroskopie sowie Massenspektrometrie charakterisiert. Die Festkörperstrukturen von 3 und 4 konnten mit Röntgenstrukturanalysen aufgeklärt werden.Danach ist beiden Verbindungen ein schichtartiger Aufbau gemeinsam, wobei im Zentrum der Schichten die interionischen Wechselwirkungen ausgebildet werden. Die Separation der Schichten folgt aus der abschirmenden Wirkung der Mesitylgruppen an der Oberfläche der Schichten.
    Additional Material: 6 Ill.
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