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  • 1
    Electronic Resource
    Electronic Resource
    The interaction of organotins with native DNA (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 6 (1992), S. 537-542 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; DNA ; Mössbauer ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The compounds R2SnCl2 and R3SnCl (R=Me, Et, nBu, nOct, Ph, in ethanol solution) as well as the aqueous species [Me2Sn(OH2)n]2+ and [Me3Sn(OH2)2]+, react with aqueous native DNA, yielding solid phases. According to the pointcharge model treatment of the 119Sn Mössbauer parameter nuclear quadrupole splitting, trans-octahedral R2Sn(O2PXY)2, and trigonalbipyramidal R3Sn(O2PXY), (R=Me, Et, nBu), would occur in the pellets, the tin atoms being coordinated by phosphodiester groups of the nucleic acid. The precipitates from Ph2SnIV would consist of the DNA complex as well as of the Ph2SnIV distannoxane obtained by hydrolysis of the reactant, whilst nOct2SnCl2, nOct3SnCl and Ph3SnCl would mainly yield stannoxanes and hydroxides. The water-soluble hydrolyzed species [Me2Sn(OH)(OH2)n]+, Me2Sn(OH)2 and Me3Sn(OH)(OH2) do not show any interaction with native DNA, although they are possibly coordinated by phosphate oxygen atoms in model aqueous systems, in the presence of excess ligand.These trends have been rationalized by QSAR approach (Quantitative Structure-Activity Relationships) in terms of electronic factors related to tin-oxygen (phosphate) Coulomb interactions, as well as the lipophilicity of R in the RnSnIV moieties.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590060611
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  • 2
    Electronic Resource
    Electronic Resource
    119Sn Mössbauer studies of bis[cysteinato(1-)-S]- and bis[penicillaminato(1-)-S]-diorganotin(IV) species in the crystalline state and in frozen aqueous solution (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 2 (1988), S. 525-531 
    Details
    ISSN: 0268-2605
    Keywords: organotin ; amino-acid ; cysteine ; penicillamine ; Mössbauer ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bonding and the configuration of the tin environment in the title compounds {R2Sn[SCH2CH(NH3+)COO-]2 and R2Sn[SC(CH3)2CH(NH3+)COO-]2, indicated in the following as R2Sn(cysH)2 and R2Sn(penH)2 respectively} has been investigated through the determination of the Mössbauer-Zeeman spectra of Ph2Sn(cysH)2 and Ph2Sn(penH)2 in the solid state, and through conventional Mössbauer spectroscopy of Me2Sn(penH)2 in the solid state as well as of Me2Sn(cysH)2 and Me2Sn(penH)2 in aqueous solution (frozen). The treatment of the data by the pointcharge model approach suggested the general occurrence of a tetrahedral C2SnS2 core. In aqueous Hepes buffer, a tertiary amino nitrogen atom has been observed to coordinate tin in Me2Sn(cysH)2 and Me2Sn(penH)2, with formation of trigonal bipyramidal tin environments. The latter solutions undergo slow decomposition reactions at room temperature. From (Me2SnS)3 occurs, as well as formation of soluble complex species in the presence of glycylglycine; Me2Sn(penH)2 appears to undergo a slow desulfuration reaction.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590020605
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and spectroscopic characterization of diethyltin (IV) derivatives of dipeptides: Crystal and molecular structure of diethyltin glycyltrosinateThis paper is dedicated to Prof. Dr. Peter Sartori with appreciation.Further X-ray structure determination data is available from the authors. (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 6 (1992), S. 75-82 
    Details
    ISSN: 0268-2605
    Keywords: Diorganotin dipeptides ; X-ray structure determination ; 13C ; 119Sn NMR ; IR ; Mössbauer ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dipeptide complexes of the diethyltin(IV) moiety, Et2SnL, have been synthesized, H2L being glycylglycine (H2GlyGly), glycylalanine (H2GlyAla), alanylalanine (H2AlaAla), glycylvaline (H2GlyVal), valylvaline (H2ValVal), glycylmethionine (H2GlyMet), glycyltyrosine (H2GlyTyr). The crystal and molecular structure of the complex Et2SnGlyTyr has been determined by singlecrystal X-ray diffraction. It consists of monomeric units, with the tin atom having a considerably distorted trigonal bipyramidal environment. The dipeptide acts as a tridentate ligand bonding the tin of the C2Sn fragment (equatorial carbon atoms) with the peptide nitrogen atom (equatorial) and axial (monodentate) carboxyl oxygen and amino nitrogen atoms, into a monomeric unit. Bond lengths and angles are reported. Infrared spectroscopic data show the occurrence of monodentate carboxyl in all solid compounds, as well as in methanol solutions of some representative complexes. 119Sn Mössbauer spectroscopic data, and their rationalization through point-charge model (literal version) calculations of the parameter nuclear quadrupole splitting (ΔE) confirm the general occurrence of trigonal bipyramidal structures of the Et2SnGlyTyr type, in the solid state, and give evidence of variations of the C—Sn—C angle in the individual Et2SnL species. Monomers occur in CH3OH solution as suggested by osmometric measurements. 13C and 119Sn NMR spectroscopic data in CD3OD show the persistence of the solid-state structures also in the solution phase, where the order of magnitude of the C—Sn—C angles, as estimated from the coupling constants |1J(119Sn,13C)|, corresponds to that shown by Et2SnGlyTyr in the solid state. 119Sn Mössbauer parameters of Et2SnGlyGly in frozen CH3OH solution are consistent with the assumptions from the NMR studies.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590060110
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis and spectroscopic characterization of dimethyl-, di-n-butyl-, di-t-butyl-and diphenyl-tin(iv) derivatives of dipeptides: Crystal and molecular structure of di-n-butyltin(iv) glycylvalinateDedicated to Prof. Dr. Mult. Dr. h.c. Alois Haas (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 6 (1992), S. 83-94 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; dipeptides ; structures ; X-ray diffraction ; NMR ; Mössbauer ; infrared ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dipeptide complexes R2SnL listed below have been synthesized: (a) Me2SnL; H2L = glycylalanine (H2GlyAla), glycylvaline (H2GlyVal), glycylmethionine (H2GlyMet), glycyltryptophan (H2GlyTrp), glycyltyrosine (H2GlyTyr); (b) nBu2SnL; H2L = H2GlyAla, H2GlyVal; (c) nBu2SnL.H2O; H2L = glycylglycine (H2GlyGly), H2GlyAla; (d) tBu2SnL; H2L = H2GlyAla, H2GlyVal; (e) tBu2SnGlyGly. H2O; (f) Ph2SnL; H2L = H2GlyAla, H2GlyVal, H2GlyTyr, H2GlyTrp; (g) Ph2Sn(HGlyVal)2. The crystal and molecular structures of nBu2SnGl Val have been determined by single-crystal X-ray diffraction. The polyhedron around tin is a distorted trigonal bipyramid, analogous to that of Et2SnGlyTyr (see Vornefeld et al., Appl. Organomet. Chem., 1992, 6: 75). According to infrared and 119Sn (ΔE parameters) Mössbauer spectroscopic data the R2SnL derivatives can be classified by their solid-state structure into two types which are distinguished by the nature of the axial carboxylate [(i) monodentate, as in nBu2SnGlyVal; (ii) bidentate]. Bonding in R2SnL.H2O and Ph2Sn(HGlyVal)2 has been discussed on the basis of vibrational data. Rationalization of the 119Sn Mössbauer parameters has been attempted by ‘literal’ point-charge model, calculations of ΔE in the structural context described above. According to 13C NMR spectra, compounds Me2SnL are undissociated in methanol solutions, whilst dissociation is inferred for aqueous solutions, probably concerning the carboxyl and amino groups only. Five-coordination in methanol and aqueous solutions has been assumed for Me2Snl from 119Sn NMR chemical shifts. Values of coupling constants |2J(119Sn, 1H)|, determined from 1H NMR spectra, gave estimates of C—Sn—C angles in Me2SnL in the range 128-136° in methanol and aqueous solutions, which correspond to values from 119Sn Mössbauer ΔE parameters (129.6-133.8°). The structural relationship of R2SnL molecules in the solid state and in solution phase has been discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590060111
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  • 5
    Electronic Resource
    Electronic Resource
    Interactions of organotins with biological systems (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 6 (1992), S. 127-138 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; biological molecules ; Mössbauer ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bonding and structure in the environments of tin atoms in organotin-biological molecules has been investigated by 119Sn Mössbauer spectroscopy, mainly through the rationalization of the nuclear quadrupole splitting parameter by pointcharge model approaches.Organotin moieties R2SnIV and R3SnIV (R = Me, nBu, Ph) generally assume trigonal-bipyramidal type configurations in membranes of human erythrocytes, when incubated with whole erythrocytes and erythrocyte ghosts at the level of micromolar (μmol dm-3) organotin per mg of membrane protein. Corresponding structures are assumed by Me2SnIV and Me3SnIV in the cytoplasm. Ethanolic Me2SnCl2 yielded distorted trans-octahedral species when reacted with ghost cells. These configurations may in principle originate through coordination of the metal by donor nitrogen or oxygen atoms from the cell constituents, such as protein side chains and related component molecules, carbohydrate fragments, and phospholipids, according to data from various model systems. Hydrolyzed species, such as bis(chlorodiorganotin) oxides and triorganotin hydroxides, could also occur for the n-butyltin and phenyltin species.The moieties Me2SnIV and Alk3SnIV (Alk = Me, Et, nBu), present as the hydrolysis products Me2Sn(OH)2 and Alk3SnOH at physiological pH in the aqueous phase (eventually coordinated by donor atoms from buffers), react with thiol groups of model molecules, as well as of feline and rat hemoglobin, forming tetrahedral or trigonalbipyramidal tin sites characterized by covalent Sn—S bonds (C2SnS, C2SnS2 and C3SnS skeletons); tin atoms are eventually further coordinated by nitrogen donors from amino acid fragments or from buffers, as well as by hydroxyl oxygen.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590060205
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis and spectroscopic characterization of R3SnIV derivatives of N-acetyldipeptides (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 7 (1993), S. 243-252 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; biocidal ; biological ; Mössbauer ; NMR ; IR ; peptide ; protein ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Triorganotin(IV) derivatives of N-acetyldipeptides R3SnAcDip; R=Me, Et, n-Bu, n-Oct, Cy or Ph (HAcDip=N-acetylglycylglycine and N-acetylglycylvaline; R=Me, n-Bu, Cy, HAcDip=N-acetylglycylalanine) were obtained by neutralization of R3SnOH and HAcDip. The complexes were studied by means of 119Sn Mössbauer, IR and 1H, 13C and 119Sn NMR spectroscopy. The C—Sn—C bond angles have been inferred by rationalization of Mössbauer nuclear quadrupole splittings as well as from NMR coupling constants. Correlations of Mössbauer isomer shifts with partial atomic charges on tin atoms have been determined: Polymeric trigonal bipyramidal structures, with near-planar R3Sn units and axial carboxylate (unidentate) and C=O amide donor groups are inferred for all the compounds in the solid state, except for Cy3SnAcGlyVal for which a tetrahedral structure is proposed. In solution the complexes are monomeric; in methanol a solvent molecule is coordinated to tin which then is still in a trigonal bipyramidal environment.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590070404
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  • 7
    Electronic Resource
    Electronic Resource
    Semi-empirical MNDO study of the structure of some diorganotin (IV) glycylglycinates (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 7 (1993), S. 495-497 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; glycylglycinates ; structures ; MNDO calculations ; tin atomic charge ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The geometrical structures of some diorganotin glycylglycinates have been obtained using the MNDO semi-empirical method. A good agreement with the experimental diffractometric data was found.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590070708
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  • 8
    Electronic Resource
    Electronic Resource
    Stannacycloalkyl and stannepinyl derivatives of dipeptides (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 8 (1994), S. 113-117 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; stannacycloalkyl compounds ; dipeptides ; Mössbauer ; NMR ; IR ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stannacyclohexyl and stannacycloheptyl derivatives of dipeptides (CH2)nSnAA · xH2O (H2AA = H2GlyGly, with n = 5, x = 2 or n = 6, x = 1; H2AA = H2GlyAla, H2GlyVal, H2GlyMet, with n = 5, 6, x = 1) and stannepinyl glycylglycinate monohydrate have been obtained by the reaction of (CH2)nSnCl2 or stannepinyl dichloride with Na2AA. According to infrared and 119Sn Mössbauer data of the solid compounds, AA acts as a tridentate ONN ligand and tin has a trigonalbipyramidal environment. An analogous structure has been inferred from 1H, 13C, and 119Sn NMR data for the undissociated molecules in methanol solution.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590080206
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  • 9
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of diorganotin(IV) derivatives of 2-mercaptopyridine and crystal structure of diphenyl pyridine-2-thiolatochlorotin(IV) (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 8 (1994), S. 397-407 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; 2-mercaptopyridine ; pyridine-2-thiolato complexes ; Mössbauer ; IR ; NMR ; crystal structure ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diorganotin(IV) derivatives of 2-mercaptopyridine (HSPy), R2Sn(SPy)2, R2SnCl(SPy) (R = Me, iPr, nBu, tBu, Cy, Ph) and Cy2SnBr(SPy), were obtained from R2SnX2 (X = Cl, Br) and NaSPy.Ph2SnCl(SPy) crystals, as determined by singlecrystal X-ray diffraction, are monoclinic in the space group P21/n. Tin forms with the bidentate SPy ligand a four-membered chelate ring with a short NSnS bite angle of 64.8(1)° leading to a heavily distorted trigonal-bipyramidal environment about tin. Apical Cl-Sn-N angle = 156.1(1)° equatorial C-Sn-C angle = 121.9(2)°. From 119Sn Mössbauer and IR data, analogous structures are inferred for the other solid compounds R2SnX(SPy), and distorted octahedral molecular structures for the solid compounds R2Sn(SPy)2 with R in the trans position, and sulfur atoms and nitrogen-donor atoms each in cis positions. According to IR and 1H, 13C and 119Sn NMR data, the solid-state molecular structures are retained in chloroform solution.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590080414
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  • 10
    Electronic Resource
    Electronic Resource
    A 119Sn Mössbauer spectroscopic study on complexes of di-and tri-organotin(IV) moieties with 2-mercaptoethanesulfonates, in the solid state and in aqueous solution (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 2 (1988), S. 457-461 
    Details
    ISSN: 0268-2605
    Keywords: Organotin ; 2-mercaptoethanesulfonates ; solid state ; solution ; Mössbauer spectra ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The configuration of the bonding environment of tin in the complexes [R2Sn(SCH2CH2SO3)2]2- (R = Me, Ph) and [Me3Sn(SCH2CH2SO3)]- has been determined to be tetrahedral both in the solid state and in aqueous solution (for the methyl derivatives). The coordination number of tin increases to five in aqueous solutions for the Me2Sn(IV) complexes in Hepes buffer (N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid; at least in fivefold excess, at pH 7.4) due to coordination by the tertiary amino nitrogen atom. No effect is detected due to the surfactant 2-hydroxypropylcellulose concerning both coordination to tin and influence on the Mössbauer parameters. The stoichiometry of mixed complex formation in aqueous solution of Me2Sn(IV), 2-mercaptoethanesulfonate and Hepes is 1:2:1, according to a procedure of ‘Mössbauer titration’. All complexes in aqueous solution undergo slow lysis of the tin-sulfur bonds. Structural assignments have been generally effected on the basis of the magnitude of experimental values of Mössbauer nuclear quadrupole splittings, measured at 77 K for both solid and frozen aqueous absorbers, and comparison with data calculated by the point-charge model approach.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aoc.590020508
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