ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Chemistry  (4,980)
  • General Chemistry  (865)
  • COMMUNICATIONS  (420)
  • Cell & Developmental Biology
  • 1970-1974  (5,592)
  • 1910-1914
  • 1970  (5,592)
Collection
Keywords
Publisher
Years
  • 1970-1974  (5,592)
  • 1910-1914
Year
  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 811-824 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The root-mean-square end-to-end distance has been calculated for a model allowing free rotation about glycoside bonds for the general case of polysaccharides having a disaccharide repeating unit. Numerical estimates are given for several naturally occurring structures based on an idealized pyranose unit in the C1 chair conformation. Extrapolation procedures which make use of the intrinsic viscosity [η] in good solvents to obtain unperturbed dimensions do not represent, data for hyaluronic acid very well, especially at low molecular weights. However, order-of-magnitude estimates suggest that this polymer behaves similarly to other polysaccharides, and probably has stiffer local structure than typical non-ionic synthetic polymers. A double logarithmic plot of the product of [η] and M̄w, the weight-average molecular weight, against the degree of polymerization in the range for M̄w of 104 to 2 × 104 permits a straight-line fit of available data for all the glycosaminoglycans, including heparin and the chondroitin sulfates, as well as sodium carboxymethyl cellulose. This result suggests similarity of short-chain hydrodynamic behavior of these polymers.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 875-875 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970) 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 865-874 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A common approximation for deriving solutions to the Lamm equation is to neglect diffusion. This paper presents a singular perturbation technique that allows one to estimate the band spreading due to nonzero diffusion coefficient. We illustrate the general mathematical technique by its application to sedimentation when pressure effects are important. Comparison of the approximate solution with accurate numerical solutions shows that the relative errors are of the order of 1% both for concentration and concentration gradient for parameters of chemical interest.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 891-896 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Glycogen acquires a negative charge in both alkaline and acidic solutions and can move in an electrical field, its mobility being related to the degree of alkalinity or acidity. There is a slight increase in relative viscosity at both ends of the pH spectrum. These effects and the changes in nuclear magnetic resonance as a function of pH are interpreted.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The viscosity of bovine liver glutamate dehydrogenase solutions was studied at 10 and 20° C in 0.2.M sodium phosphate buffer at pH 7, in the concentration range 0.1-8 mg/ml. A method for the study of the viscosity of very dilute solutions of associating enzymes is described. It was found that the reduced specific viscosity ηsp/c of glutamate dehydrogenase continuously increases with increasing enzyme concentration, from about 4 ml/g at the lowest concentrations to about 16 ml/g at 8 mg/ml. In the presence of 10-3M GTP and 10-3M NADH the viscosity increase is much smaller and the results can be extrapolated to zero enzyme concentration to yield an intrinsic viscosity [η] = 3.2. The values of ηsp/c in phosphate buffer alone apparently extrapolate to the same value of [η], or to a value close to it. We also observe that, in the presence of toluene ηsp/c increases very much more with enzyme concentration: ηsp/c already equals 16 ml/g at a concentration of 0.75 mg/ml. These observations are in good agreement with the hypothesis that the active oligomer of glutamate dehydrogenase (MW = 312,000) associates with increasing enzyme concentration to form linear rodlike polymers of indefinite length. This association is strongly diminished by the addition of 10-3M GTP, 10-3M NADH. Toluene, on the other hand, promotes reversible association to linear polymers of very high molecular weight. The transverse and axial rotary frictional coefficients of macroscopic bodies, similar to a physical model for the structure of glutamate dehydrogenase recently advanced, were determined. Assuming that the viscosity of the model is equal to that of an ellipsoid of rotation with identical frictional coefficients, we calculate [η] = 3.26 ml/g according to Kuhn and 3.20 ml/g according to Simha, for the glutamate dehydrogenase oligomer, in good agreement with the result derived from the study of enzyme solutions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 911-922 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular monolaycrs of poly(β-benzyl L-aspartate) spread at. an air-water interface have been studied. The results obtained both by direct observations on the monlayer and from examination of collapsed films with polarized infrared spectroscopy and electron diffraction are consistent with the presence of right handed α-helices in the mono-layer when the molecular weight is high. When 1% (v/v) isopropanol is present in the subphase the right-handed helix prevails, provided that the monolayer is first spread on water. Monolayers of low molecular weight polymer appear to form the crossed-β structure. Orientated collapsed films of high molecular weight polymer can be converted to the left-handed α-helical and to the ω-conformation, and the mechanisms are discussed. The surface chemistry of this polymer is compared with that of related polymers and a consistent pattern of behavior emerges.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1017-1028 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low-angle light scattering results reported previously demonstrated that measurements on high molecular weight native DNA must be made at angles below 30° in order to obtain correct molecular weights. Earlier light-scattering data obtained on denaturated DNA at angles above 30° showed no change in molecular weight upon denaturation, even though other techniques clearly showed that strand separation occurred. This paper reports low-angle measurements on solutions of calf thymus and T7 DNA denatured under acidic conditions. The results demonstrate that a halving of molecular weight consistent with strand separation is detected by light scattering only when low-angle data are used to obtain correct molecular weights for native material. As expected from theoretical considerations, the scattering from denatured DNA is a linear function of sin2(θ/2), where θ is the angle of observation. This result shows that anticipated experimental artifacts have no significant effect on the low-angle measurements and demonstrates that the curvature in the scattering envelope observed for native DNA below 30° is an inherent property of the native molecule.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics for the cis-trans isomerization of long-chain poly-L-proline has been studied as a function of pressure, temperature, and solvent composition in the acetic acid + n-propanol solvent system. Our complete kinetic curves were fitted by Monte Carlo techniques, and rate constants for nucleation, growth, and termination were estimated. It was found that for the formation of a cis-helix, high pressure, low temperature, and increased acetic acid content of the solvent, lowered the rate of nucleation relative to growth. The inverse seems to be t rue for the formation of a trans-helix. Molecular models suggest that this behavior of the kinetic constants can be due to the exposure of peptide units to solvent in the transition state for trans nucleation, and the burying of peptide units in the transition state for cis nucleation. It is further suggested from our analysis of complete kinetic curves that at least one of the assumptions usually made in the analysis of relaxation kinetics is invalid for poly-L-proline.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1039-1047 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solutions of amylose in ethylenediamine yield a crystalline film complex upon evaporation of solvent. The x-ray analysis indicates the presence of a tetragonal-shaped cell with a symmetry approximating that of space group P212121. The amylose sixfold helix has a diameter of 13.3 Å and a translation period of 8.0Å. Chemical and physical analyses support a complexing ratio of one ethylenediamine molecule to every two glucose units. The structure is nearly identical to any amylose-dimethyl sulfoxide complex previously examined. The square mode of packing arrangement appears to result from complexation between amylose chains. Such complexing indicates a much greater degree of amylose interaction than is observed in amylose complex structures having a hexagonal close-packing arrangement.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1049-1058 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: pH titration measurements of poly- S-carboxymethyl-L-cysteine were undertaken in the aqueous Nacl solution in relation to the β form-random coil transition. The titration curves show a marked molecular weight dependence because of the shortened chain length of materials. Comparison of the optical rotatory dispersion parameter a0 with the titration curve reveals that the titration curve apparently reflects a β structure-random coil transition. The β form of this polymer is assumed to be an intramolecular β form, rather than a β structure stabilized by an intermolecular hydrogen bond, at least in the polymer concentration range considered here. The standard free energy change per amino acid residue for the transition from un-ionized random coil to un-ionized β form is estimated to be about -750 cal/mole residue in the range of 0.005-0.2M NaCl concentration.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1059-1077 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The circular dichroism (CD) spectra of the four usual deoxymononucleosides, all sixteen deoxydinucleotides, and a number of trinucleotides have been measured. The dimer spectra are quite different from the sum of the spectra of their constituent monomers. This indicates the presence of base-stacked conformations analogous to those found for ribonucleoside diphosphates. The CD spectra of several deoxytrinucleotide diphosphates and single-strand f 1 DNA can be calculated fairly well by using a semi-empirical nearest-neighbor approach. There is little or no effect of terminal phosphate or of salt concentration on the optical properties of most deoxy oligomers. The possibility of simultaneous analysis of mixtures of deoxypurine or deoxypyrimidine sequence isomers has been examined. This seems to be a viable approach for the analysis of purine runs but cannot promise much success for pyrimidine runs.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1079-1103 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The circular dichroism spectra of all 16 ribodinudeoside phosphates containing the bases adenine, uracil, cytosine, and guanine have been measured at room temperature and neutral pH. These results are compared with the circular dichroism spectra of the corresponding deoxy compounds. From the optical properties it is clear that the geometry of the base-stacked conformation of ribo compounds must differ substantially from that of deoxy compounds. Because of this, it is not possible to draw firm conclusions about the relative extent of stacking in most ribo and deoxy compounds. The optical rotatory dispersion of about a dozen deoxy and ribodinucleoside phosphates has been studied as a function of temperature. These results confirmed the conclusions drawn earlier from measurements at a single temperature. Several dinucleoside phosphates containing a 2′ → 5′ phosphodiester bond have also been examined. These compounds have a substantial degree of base stacking at room temperature. The geometry of the stacked conformation is different from that of either the normal ribo dimer or the deoxy dimer. The role of the 2′-hydroxyl group in stabilizing base stacked geometries has been examined by studies on C-2′-O-methyl-pC. This compound has optical properties almost identical to those of CpC. This suggests that the effect of the 2′ hydroxyl is felt indirectly through its perturbation of the geometry of the sugar ring rather than directly by hydrogen bonding. It is not possible at present to identify precise conformational differences among deoxy-, ribo-and 2′ → 5′ ribodinucleoside phosphates.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1119-1124 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1349-1360 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The influence of single-strand breaks on the kinetics of the relaxation of DNA in a solution of low ionic strength has been investigated by a temperature jump method. The relaxation of DNA after a jump of 0.7 °C in the melting region has been monitored by measuring the extinction at 260 nm. For essentially monodisperse T4 DNA (M = 130 × 106) two distinct relaxation times have been observed, that depend markedly on the initial extent of denaturation 1 - θ. The larger relaxation time decreases from 450 sec to about 300 sec, the smaller one from 55 see to 30 when 1 - θ increases from 0.03 to about 0.8. The dependence of these relaxation times on the average number of single-strand breaks per molecule (p) appears to be very small up to p = 100. However, the relative contribution of the slow process decreases sharply when p increases from 0.6 to 30 and remains nearly constant for larger p. The observations are discussed in the light recent theories of the kinetics of denaturation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1361-1372 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Measurements have been made of the intensity of light scattered from aqueous solutions of calf thymus DNA with and without the application of electric fields. For fields approaching 150 V/cm and frequencies below 2.5 KHz, changes (ΔI) of up to 10% in the residual scattered intensity were observed. In agreement with previous dielectric and electric birefringence measurements, a low frequency dispersion of ΔI was observed, from which a rotary diffusion constant (D) of 1200 s-1 was determined. Interpreting the electric field data in terms of the classical dipolar orientation theory led to values of 2.4 × 10-25 cm (7.4 × 10-14 esu) and 4.3 × 10-25 cm (13 × 10-14 esu) for the permanent dipole moment and the anisotropy of the electric polarisabilities respectively. Furthermore the permanent dipole moment was along the major molecular axis and the particles orientated in the field as rigid entities. The zero field data indicated a molecular shape which was not rodlike but corresponded to the Kratky-Porod “stiffness” parameter of x = 24 for the wormlike coil model. Although curved, the molecules appeared to orientate in low-intensity electric fields as rigid, but not rodlike molecules. The implications of this on recent discrepancies in D determined by two or more dynamic relaxation methods is briefly discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1391-1402 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The buoyant density of T-4 DNA was determined by equilibrium sedimentation in a density gradient, of mixed solutions of cesium and magnesium chlorides and bromides. The preferential hydration was calculated from these data, allowing appropriately for the exchange equilibrium of DNA with Cs+ and Mg++ ions. The charge and intrinsic solvation of the counterions were found to have no appreciable effect on the hydration of the DNA, the extent of solvation depending only on the thermodynamic, activity of the water. Various reasonable hypotheses are discussed to account for these results.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1373-1389 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of 27 SMS2 RNA with formaldehyde normally results in an unfolded, 13.4 S form. At acidic pH, however, and under the proper ionic conditions, a compact component sedimenting at 36-40 S was obtained. The molecular weight of this species corresponds to a dinner. The formaldehyde concentration was not critical, and approximately the same number of base pairs had been opened in the compact and in the unfolded form. Presumably dimers, which had been specifically formed under defined conditions, were stabilized by formaldehyde-induced crosslinks. Similar dimers were formed by 16 S and by 23 S ribosomal RNA, but not by tRNA.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 26-32 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 44-50 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 51-54 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 37-43 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 35-36 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 55-60 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 61-62 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 63-63 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 445-457 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The change in apparent molal volume φ of DNA on thermal denaturation in carbonate buffer at pH 11.0 has been determined by the dilatometric method. It was found that φ increases sigmoidally during the helix-coil transition. Several methods, including a colorimetric technique that closely simulates the conditions used in the dilatometric experiments, were employed to estimate the protons lost by the DNA during the transition. These measurements indicated that the extent of the proton loss depends on the counterion present, increasing in the order Li+ 〈 Na+ 〈 K+ 〈 Cs+. The major part of the volume changes observed during the denaturation is due to the volume changes expected to accompany the transfer of protons from the bases guanine and thym ne to carbonate ions. As has been previously reported for the denaturation of DNA at neutral pH, the volume change directly due to the change in shape of the polymer molecules is so small as to be experimentally undetectable.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 569-588 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The coupling of theoretical optical calculations with experimental data provides a check of the validity of the theory or provides conformational information. The theory was validated by studies in which the approximate conformation was located independently. These studies have shown that a theory restricted to the two lowest energy transitions for each chromophore gives qualitative agreement with experiment. On the other hand, for some of the proline derivatives, the theoretical treatment allows detailed conformational assignments. Both successes and failures in correlating theory with experiment are discussed. The results presented provide a basis for assessing the prospects for relating protein and polypeptide optical activity to their conformations.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ethidium bromide inhibits the formation of ultraviolet-induced pyrimidine dimers in DNA. The efficiency of dimer inhibition increases with increasing energy of the exciting photons. The efficiency of energy transfer from the DNA singlet to the dye singlet, as monitored by sensitized fluorescence, is independent of wavelength. The efficiency of singlet-singlet transfer agrees with that for dimer inhibition at photon energies corresponding to excitation of the lowest singlet state of DNA. Our results support a model in which dimers are formed both directly from the singlet state and also from the triplet state, with triplets arising from higher vibrational levels of the singlet.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 689-696 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intercalation model of DNA-hydrocarbon binding appears reasonable, but rests on indirect evidence only. To test the model, a size criterion for binding has been proposed. The size criterion is based on the assumption that hydrophobic forces play a major role in the binding of hydrocarbons to DNA. It states that hydrocarbons which are small enough to intercalate into DNA and be well protected from contact with the medium, will be found to bind to DNA; those that are too large will not. We report results on the binding of fourteen polycyclic aromatic hydrocarbons to DNA. Predictions based on the size criterion were found to be valid in all cases tested.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 697-715 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dialysis data of Huang and Ts'o for the cooperative binding of adensine to polyuridylic acid are analyzed here using a grand-partition function Ising model method similar to that originally employed for polyelectrolytes by Rice and Nagasawa. An appropriate modification permitting the treatment of the sliding degeneracy of the two polyuridylic acid strands is also included. In addition to the previously estimated stacking energy of about -6 kcal/mole one also obtains the free energy change F̄ for the transfer of a single adenosine molecule from a fixed site in solution to a fixed site on the polyuridylic acid. This binding energy falls in the range F̄ = -140 to +620 cal/mole, indicating that binding in the 1:2 (purine: pyrimidine) complex is either very weak or repulsive. The absence of any comparable cooperative stacking of adenosines in solution at the same concentration together with the likely repulsive character of the binding implies that the stacking energy must contain a significant contribution from other processes than simple stacking of adenosines. A generalization of the theory to treat multicomponent binding and longer-range interactions is effected, and the form applicable to simultaneous binding of both adenosine and guanosine by polyuridylic acid is presented.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 739-744 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present communication describes a new way of studying helix-random coil transformations of polypeptide, poly-(γ-benzyl L-glutamate), in benzene-trifluoracetic acid (TFA) and chloroform-TFA systems. The difference between the PMR chemical shift of TFA with and without the polypeptide, measured as Δ, may be used to follow the conformational transition. This technique is particularly useful for concentrated solutions, where the PMR peaks of the polymer are so broad that no valuable information may be derived. As the TFA content increases in the system (at constant polymer concentration), Δ decreases normally whether the polymer is helical or random. However, Δ changes in a different way in the helix-random coil transition region, and actually increases with increasing TFA content. This peculiar behavior is explained in terms of the solvation of the helix and random coil structures.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 745-748 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 717-738 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new procedure for evaluating u and σ characterizing σ-helix-forming polypeptides in solution was derived from Nagai's theory for the helix-coil transition of such polymers. Here u is the activity for helix formation from random coil, and σ is the helix initiation parameter. The necessary data are the helical content fN at fixed solvent and temperature as a function of N, where N is the degree of polymerization of the polypeptide sample. Such data were obtained from ORD measurements on a number of fractionated samples of poly-N5-(3-hydroxypropyl)-L-glutamine (PHPG) in mixtures of water and methanol covering the complete range of composition and at various termperatures (5-40°C). When analyzed in terms of the proposed procedure, they yielded values of σ which were in the range (3.2 ± 0.6) × 10-4, substantially independent of solvent composition and temperature. These values were much larger than those obtained recently for σ of poly(β-benzyl-L-aspartate) in m-cresol and in a mixture of chloroform and DCA. The data for [η] and s0 (limiting sedimentation coefficient) as functions of molecular weight indicated that the molecular shape of PHPG in pure methanol is essentially rodlike, whereas that in pure water is not entirely randomly coiled but rather may be regarded as an interrupted helix. These indications were consistent with the results from ORD measurements. When plotted against the corresponding values of fN, the values of [η] and [s0] for PHPG in mixtures of water and methanol of various compositions and temperatures formed smooth composite curves, and we attributed these phenomena to the fact that σ of PHPG was nearly constant under these solvent conditions. Here [s0] stands for a reduced limiting sedimentation coefficient which is equal to the inverse friction factor of the solute molecule.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970) 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 765-782 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction of purine with DNA, tRNA, poly A, poly C, and poly A. poly U complex was investigated. In the presence of purine, the nucleic acids in coil form (such as denatured DNA, poly A and poly C in neutral solutions, or tRNA) have lower optical rotations. In addition, hydrodynamic studies indicate that in purine solutions the denatured DNA has a higher viscosity and a decreased sedimentation coefficient. These findings indicate that through interaction with purine, the bases along the poly-nucleotide chain are unstacked and are separated farther from each other, resulting in increased assymmetry (and possibly volume) of the whole polymer. Thus, the de-naturation effect of purine reported previously can be explained by this preferential interaction of purine with the bases of nucleic acids in coil form through a hydrophobic-costacking mechanism. Results from studies on optical rotation and helix-coil transition show that the interaction of purine is greater with poly A than with poly C. The influence of temperature, Mg++ concentration, ionic strength, and purine concentration on the effect of purine on nucleic acid conformation has also been investigated. In all these situations the unraveling of nucleic acid conformation occurs at much lower temperatures (20-40°C lower) in the presence of purine (0.2-0.6M).
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The characteristic ratio of unperturbed cellulose chain was computed as a function of the angle τ at, the bridge oxygen atom and the degree of polymerization. Very high values of the order of 40 or more, depending on the angle at the bridge oxygen atom, have been obtained for this ratio, indicating that cellulose chains are highly extended. The average dimensions of cellulose chains are found to be sensitive even for small changes in the angle at the bridge oxygen, and these chains attain the character of a random coil in very high molecular weight range (degree of polymerization greater than 2000). The large differences in the unperturbed dimensions of cellulosic chains observed in different solvents have been attributed to the possible small changes in the angle τ caused by specific solvent, interactions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conformational properties of block copolymers of poly-L-leucine in water have been examined. The degree of polymerization of the poly-L-leucine block was 11 and 21, respectively, for samples prepared by the Merrifield procedure, and 56 for a sample prepared by the polymerization of leucine N-carboxyanhydride. The optical rotatory dispersion parameter b0 was used to obtain the helix content θh at various temperatures. Application of the Lifson-Roig theory gave the following parameters for the transition of a residue from a coil to a helical state: v = 0.05-0.011, ΔH = +100 cal/mole, ΔS = +0.70-1.00 e. u. These parameters, as well as those for other polyamino acids, are accounted for by hydrophobic bonds involving the nonpolar side chains in the helical and randomly coiled forms. From the data for poly-L-alanine and theoretical values of the thermodynamic parameters for hydrophobic bond formation, the parameters for formation of a polyglycine helix are computed. By separating the contributions of the backbone, it is possible to obtain a set of thermodynamic parameters for the side-chain contributions of a number of polyamino acids. Increased size of the nonpolar side chain (with a larger contribution from hydrophobic bonding) makes a larger contribution to the stability of the α-helix which is reflected, among other ways, in a higher helix content at given temperature.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of DL-β-phenylalanine N-carboxyanhydride (NCA) initiated by poly(N-benzylglycine)diethylamide (DEA) and poly(N-methyl-DL-alanine)DEA has been investigated. As previously reported, polysarcosine DEA, poly-N-ethylglycine DEA, and poly-N-n-propylglycine DEA showed marked accelerations in the polymerization of DL-β-phenylalanine NCA as compared with the polymerization initiated by low molecular weight, amines having similar base strength. However, this phenomenon (the chain effect) was not observed with the two polymer catalysts studied in the present investigation With poly-N-methyl-DL-alanine DEA, adsorption of DL-β-phenylalanine NCA onto the polymer chain takes place, though not so effectively as with other polypeptides, so the absence of chain effect was ascribed to a reduced flexibility of the polymer chain. With poly(N-benzylglycine)DEA, the reactivity of terminal base group was found to be much lower than that of other polymer catalysts. However, the absence of the chain effect would be attributed to the rigidity of polymer chain of poly-N-benzylglycine DEA due to the bulkiness of the N-benzyl group.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 799-810 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular weights by osmometry (M̄n), light scattering (M̄w), and sedimentation-diffusion (MsD) were determined for selected fractions and unfractionated samples of hyaluronic acid in the molecular weight range 3 × 104-1.7 × 106. For the determination of MsD from the sedimentation coefficient s, a calibration procedure based on the data of Laurent, Ryan, and Pietruszkiewicz gave the following relations in 0.2M NaCl: log (s-1)0 = 14.681 - 0.413 log MsD and log D0 = -3.828 - 0.568 log MsD, where subscript, zero refers to zero concentration and D is the diffusion coefficient. The average Mandelkern-Flory parameter β in 0.2M NaCl is 3.0 × 106. Data for the intrinsic viscosity [η] may be fitted for M 〉 105 by [η] = K′Ma, where K′, a are in 0.2M NaCl, 0.0228, 0.816; in 0.5M NaCl, 0.0318, 0.777; in 0.1 M HCl, 0.0279, 0.763, respectively. Below M = 105, [η] appears to fall below the values calculated, possibly due to non-Gaussian behavior of short chains. The second virial coefficient A2 in 0.5M NaCl approaches the ideal Donnan value, decreasing slightly with increasing molecular weight. The friction parameter P is about 20% smaller than that of uncharged polymers of similar dimensions. The flexible coiling nature of this polymer is confirmed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 843-864 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The formation of a slowly sedimenting form of 23-S ribosomal RNA from E. coli has been investigated by analytical ultracentrifugation and thermal denaturation in aqueous solution and in formamide. Evidence is presented that the slow form of 23-S arises as a result of nucleate damage to the RNA in the 50-S ribosome. The 30-S ribosome (and 16-S RNA), is unaffected. The slow form of 23-S RNA cannot be demonstrated under conditions of complete denaturation in formamide, but only by partial denaturation in aqueous solution of low ionic strength (〈 0.01M Na). Apparent maintenance of the integrity of 23-S RNA in formamide after nuclease treatment suggests that this may not be a simple linear molecule. An alternative model is suggested containing a circular element in the structure.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 825-842 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Uniform LiDNA fiber specimens of nearly 20 m length have been prepared with a wet-spinning method developed by the author. Samples immersed in the spinning bath (80% ethyl alcohol containing 0.4M LiCl) have been subjected to mechanochemical study involving stretching, relaxation, and contraction measurements. A special technique was developed to transfer the sample from the Teflon-coated cylinder used in spinning to the sample column of the mechanochemical apparatus without stretching or removing the sample from the spinning bath. Force-strain curves of samples consisting of two fiber bundles showed an initial region of low slope followed by a region of high slope and a second region of low slope up to rupture. Some thicker specimens showed an aging effect which abolished the initial low-slope region and was interpreted as indicative of crystallization. Force-strain curves of two-bundle samples showed a strong influence of temperature with a complete loss of tensile strength of the LiDNA fibers in the spinning bath at about 55°C. Furthermore, samples at zero strain exhibited a contractile force when subjected to temperatures above about 40°C; the contractile process was pronounced with samples kept above 48°C. On contraction these samples obtained a zero-force length 20-30% of the original. These data are taken as evidence for a helix-to-coil transition occurring in the DNA, the low melting temperature being caused by the chemical influence of the ambient aqueous alcohol-LiCl bath.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1029-1038 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecular weight of native DNA is shown to decrease by at least a factor of two on denaturation by heat or alkali. This result is obtained only if low-angle (〈30°) light-scattering measurements are used. High-angle measurements (〉30°) do not reveal a decrease in molecular weight on denaturation due to the incorrect value for native DNA. The dn/dc value for both native and denatured DNA is 0.166 ml/g ± 0.003 ml/g. Methods are described for the clarification of native and denatured DNA solutions for light scattering by the use of membrane filters.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 991-1000 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electric dichroism studies on poly(γ-benxyl L-glutamate) show that the addition of small amounts (up to 5%) of trifluoroacetic acid causes complete disappearance of dichroism in contrast to the electric birefringence, which drops to an observable plateau at 20% of its initial value. This loss of dichroism cannot be explained simply by a decrease in the effective dipole moment of the benzyl ester side chains, and the nature of this interaction is explored by nuclear magnetic resonance and infrared spectral studies. Theories of the helix-coil transition which require an initial protonation of the helix backbone to form a more flexible rod consisting of helical segments interrupted by regions of random coil are shown to be inadequate to describe the changes in poly(γ-benzyl L-glutamate) effected by small amounts of trifluoroacetic acid. Rather, trifluoroacetic acid in small amounts interacts with the ester carbonyl oxygen in the side chain, either by hydrogen bonding or protonation, before there is evidence of any effect on the backbone or of loss of helix content.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1229-1237 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Raman spectra of poly-L-lysine hydrochloride and poly-∊-carbobenzoxy-L-lysine in the solid state have been obtained and are consistent with the presence of an α-helical structure. The Raman spectrum of poly-L-lysine in aqueous solution suggests the presence of random coil structures.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970) 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The nonbonded interaction energy of disaccharides, mannobiose and galactobiose and polysaccharides mannan and galactan have been computed as a function of dihedral angles (φ,ψ). The conformation (40°, -20°) has been preferred for the mannan chain from nonbonded interaction energy considerations. The O5…O3′ type of intramolecular hydrogen bond has been found to be possible in the above conformation. Comparison of the allowed region of mannan with those of cellulose and xylan indicates that the monomer unit, in mannan chain has slightly higher freedom of rotation than that of cellulose and less than that of xylan. As in cellulose and mannan, the freedom of rotation of the monomer units in β-1,4′ galactan is highly restricted. Unlike mannan (which prefers an extended conformation) the β-1,4′ galactan prefers a helical conformation similar to amylose. Just as in amylose the O2…O3′ type hydrogen bond between contiguous residues is also possible in β-1,4′ galactan.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1475-1502 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The predictions of the presently accepted molecular exciton model for the optical activity of helical polypeptides are in reasonable agreement with experimental spectra in the accessible wavelength range. However, crucial verification requires the detect of a significant negative rotatory hand just below the accessible range. A computer-oriented method is utilized to obtain information concerning the inaccessible range. Optical rotatory dispersion computed by evaluation of the Kronig-Kramers integral transform from the experimentally determined circular dichroism of several helical homopolypeptides in solution are compared with the experimentally determined optical rotatory dispersion. Computed and experimental curves are congruent within an uncertainty approaching that of the experimental technique, whatever the polypeptide sample lot, side chains, and solvent. It is shown that t his agreement is not a computational or experimental artifact. These results can be interpreted in two ways: (1) that the predicted band does not exist, and (2) that the perturbation of the predicted band is being negated by other inaccessible bands in the vacuum ultraviolet. Arguments are presented to show that the first of these two possibilities is more probable.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 9 (1970), S. 1511-1530 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The potential problem is formulated for rodlike macroions and reduced to a single dimensionless equation with appropriate boundary conditions. A method of solution based on piecewise linearization of the potential equation is detailed and compared with two other approaches. It is suggested that the present method yields improved estimates of macroion charges. Some numerical results are included, and the relation between electrophoretic charge and macroion charge is considered.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 65-65 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 66-68 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 69-80 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 95-98 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 129-132 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 152-158 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 159-162 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970) 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 163-164 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 177-179 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 165-176 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 180-187 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 188-193 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 194-194 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 4 (1970), S. 197-198 
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 104-111 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation and Properties of FluoromethyldialkylaminesFluoromethyldialkylamines (3a-f) are prepared from N,N-acetals (aminals) by cleavage with carboxylic acid fluorides or l-fluoro-2,4-dinitrobenzene. They are low-boiling liquids and are characterized by a covalent carbon-halogen bond. Their reactivity is similar to that of the analogous carbimonium chlorides, bromides and iodides.
    Notes: Fluormethyl-dialkyl-amine (3a-f) werden durch Spaltung von Aminalen mit Carbonsäurefluoriden oder l-Fluor-2.4-dinitro-benzol gewonnen. Sie sind niedrigsiedende, durch eine kovalente Kohlenstoff-Halogen-Bindung charakterisierte Flüssigkeiten und zeigen ähnliche Reaktionsfähigkeit wie die analogen Carbimoniumchloride, -bromide oder -jodide.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 133-146 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterosubstituted Fulvenes, IV In the 5-Membered Ring Unsubstituted 6,6-DiaminofulvenesAlkylation of tetrasubstituted thioureas with methyl iodide leads to S-methyl isothiuronium iodides 3, which have been transformed to 6,6-diaminofulvenes 1 by condensation with cyclopentadienyl sodium. Some compounds of type 1 are also obtainable from the reaction between cyclopentadiene and chloroformamidinium chlorides 4 in the presence of triethylamine. I.r., u.v., and n.m.r. spectra of 1 and 3 are discussed.
    Notes: Tetrasubstituierte Thioharnstoffe lassen sich mit Methyljodid in die S-Methyl-isothiuroniumjodide 3 überführen, die ihrerseits mit Cyclopentadienylnatrium die 6.6-Diamino-fulvene 1 bilden. Einzelne Vertreter von 1 sind auch aus Cyclopentadien und Chlorformamidinium-chloriden 4 in Gegenwart von Triäthylamin zugänglich. Die IR-, UV- und NMR-Spektren von 1 und 3 werden diskutiert.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 183-192 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: VinylsulfonylmethylidsThe preparation of dimethylsulfonio-(vinylsulfonylphenylsulfonylmethanide) (5), triphenyl-phosphonio-(vinylsulfonylphenylsulfonylmethanide) (6) and triphenylphosphonio-(vinyl-sulfonylbenzoylmethanide) (8) is described. The u. v. spectra of 5 and 6 are similar to the u.v. spectrum of the bis(phenylsulfonyl)methane anion (9). Because of the interaction of the SO2-groups with the ylide carbanions, the SO2-stretching frequencies compared to those of vinylsulfonylphenylsulfonylmethane (4) are shifted 20 -30/cm to lower wave numbers. This interaction causes a higher electron density in the vinyl groups of the ylids compared to 4, as shown by n. m. r. measurements. The mass spectra of 5, 6 and 8 are discussed.
    Notes: Die Synthese von Dimethylsulfonio-[vinylsulfonyl-phenylsulfonyl-methanid] (5), Triphenyl-phosphonio-[vinylsulfonyl-phenylsulfonyl-methanid] (6)undTriphenylphosphonio-[vinyl-sulfonyl-benzoyl-methanid] (8) wird beschrieben. Die Elektronenspektren von 5 und 6 sind mit dem UV-Spektrum des Bis-phenylsulfonyl-methan-Anions (9) vergleichbar. Durch Wechselwirkung der SO2Gruppen mit den Ylidcarbanionen werden die SO2-Valenzschwingungsfrequenzen im Vergleich zu Vinylsulfonyl-phenylsulfonyl-methan (4) um 20 - 30/cm zu kleineren Wellenzahlen verschoben. Diese Wechselwirkung bedingt eine höhere Elektronendichte in den Vinylgruppen der Ylide als bei 4, was NMR-spektroskopisch nachweisbar ist. Die Massenspektren von 5, 6 und 8 werden diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 173-182 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Cyclopentadienones with Aliphatic Diazo Compounds, 6 Experiments with „Indanocyclone“„Indanocyclone“ 3, prepared from ninhydrin (1) and dibenzylketone (2), reacts with an ethereal diazomethane solution to form an 1 :1-adduct 4a and two isomeric 1 : 2-adducts, presumably 12 and 13. Elimination of N2 from 4a leads to the formation of the cyclopropane 7, the fluorenone 6 and, by way of phenyl migration, the new cyclone 8a; elimination of N2 from 12 and 13 leads to undefined products. 5 is converted via its hydrazone into the diazo compound 10. Ring enlargement of 6 with diazomethane produces the phenanthrene 9.Reaction of diazoethane with 3 gives the instable 1 :1-adduct 4b, which yields the new cyclone 8b by N2-elimination and phenyl migration. 8b also forms an 1 :1-adduct (11?). Phenyl diazomethane adds to 3 giving a rather stable 1 :1-adduct 14, the isomeric 16 and the epoxide 15. Elimination of N2 from 14 yields the fluorenone derivative 17, which upon treatment with excess diazomethane undergoes ring enlargement to form the phenanthrene derivative 18.
    Notes: Das aus Ninhydrin(l)und Dibenzylketon(2) erhältliche, Indanocyclon‘ 3 gibt mit ätherischer Diazomethanlösung ein 1 :1-Addukt 4a und zwei isomere 1 : 2-Addukte, vermutlich 12 und 13. 4a zerfällt unter N2-Abspaltung zum Cyclopropanderivat 7, zum Fluorenonderivat 6 und unter Phenylwanderung zum neuen Cyclon 8a; 12 und 13 geben bei der N2-Abspaltung keine definierten Produkte. Aus 5 wird über sein Hydrazon die Diazoverbindung 10 und mit Diazomethan unter Ringerweiterung das Phenanthrenderivat 9 erhalten.Mit Diazoäthan entsteht aus 3 das instabile I :1-Addukt 4b, das bei der N2-Abspaltung unter Phenylwanderung das Cyclon 8b bildet; dieses gibt erneut ein Diazoathan-Addukt (11?).Mit Phenyldiazomethan liefert 3 ein ziemlich stabiles 1 :1-Addukt 14 und sein Isomeres 16 sowie das Epoxid 15. Bei der N2-Abspaltung entsteht aus 14 das Fluorenonderivat 17, das mit Diazomethan zum Phenanthrenderivat 18 ringerweitert wird.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 222-235 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Orthoamides, X: Reaction of Vinylogous Amide Acetals, Aminalesters and Amide AminalsDerivates of vinylogous orthoformic acid amides react with Grignard compounds to give l,3-bis(dimethylamino)-l-alkenes (4-7), with methylene active compounds to give derivates of N.N-disubstituted 4-amino-l,3-butadienes (17  - 29) and with primary aromatic amines to form vinylogous, N,N,N′-trisubstituted amidines (31-36, 38-40).
    Notes: Vinyloge Orthoameisensäureamid-Derivate geben mit Grignard-Verbindungen 1.3-Bis - dimethylamino-alkene-(l) (4-7), mit methylenaktiven Verbindungen N.N-disubstituierte 4 - Amino-butadien-(l.3)-Derivate (17-29) und mit primären aromatischen Aminen vinyloge N.N.N′-trisubstituierte Amidine (31-36, 38-40).
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 17-22 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pyrimidines, VIII Synthesis and Properties of Uracil-4-carbaldehyde Hydrazone. The First Inner Orbital Complex of a Pyrimidine with CopperUracil-4-carbaldehyde (1) reacts with stoechiometric amounts of hydrazine to yield the azine 2. Under mild conditions (30 per cent hydrazine, room temperature) the azine is cleaved to uracil-4-carbaldehyde hydrazone (3). This cleavage by hydrazine is typical for the azomethine group in position 4 of the uracil ring. In aqueous or aqueous-alcoholic solution 3 reacts readily with aliphatic, aromatic and heterocyclic aldehydes to form mixed azines in good yield. With copper(II)-acetate 3 yields in aqueous solution a new type of symmetrical inner orbital complex in which the ratio of pyrimidine to copper is 2 :1. The crystalline and insoluble paramagnetic complex 13 presumably has a planar structure. Substitution of the amino group, even with a methyl group, prevents complex formation. 13 is decomposed by mineral acids to the respective copper salt and azine 2. In analogy to 1 2-thiouracil-4-carb-aldehyde forms the corresponding hydrazone 12.
    Notes: Uracil-carbaldehyd-(4) (1) liefert mit stöchiometrischer Menge Hydrazin das symmetrische Azin 2, welches unter milden Bedingungen (30proz. Hydrazin, Raumtemperatur) zum Uracil-carbaldehyd-(4)-hydrazon (3) gespalten wird. Die schonende Hydrazinolyse ist spezifisch für die Azomethingruppe in 4-Stellung des Uracilrings. 3 liefert in wäßriger bzw. Wäßrig-alkoholischer Lösung mit aliphatischen, aromatischen und heterocyclischen Aldehyden in guter Ausbeute gemischte Azine. Mit Kupfer(II)-acetat bildet 3 einen neuartigen symmetrischen Innerkomplex der Art Pyrimidin : Kupfer = 2:1. Analog zu Uracil-carb-aldehyd-(4) (1) erhält man aus 2-Thio-uracil-carbaldehyd-(4) mit Hydrazin das entsprechende Hydrazon 12.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 46-49 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Crystal Structure of l,2,3,4,4a,9a-hexahydro-4a,9-propanocarbazolium HydrobromideThe crystal structure of the title compound has been determined by X-ray structure analysis. From these results a twist angle of 64.5° of the orbital of the nitrogen is derived.
    Notes: Auf röntgenographischem Weg wurde die Kristallstruktur der Titel-Verbindung bestimmt. Aus den so erhaltenen Ergebnissen resultiert ein Verdrillungswinkel des Orbitals am Stickstoff von ϕpH = 64.5°.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 76-81 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Enthalpy of Formation of Tungsten Hexafluoride and Tungsten PentafluorideThe heat evolved on combustion of tungsten and tungsten pentafluorid in fluorine was measured in a bomb calorimeter. The enthalpies of formation calculated from these values were found to be ΔH°298(WF6, g) = -411.7 ± 0.5 kcal mol-1 and ΔH°298 (WF5, c) -346.1 ± 2.6 kcal mol-1.
    Notes: Die Verbrennungswärmen von Wolfram und Wolframpentafluorid in Fluor wurden in einem Bombenkalorimeter gemessen. Die aus den Meßdaten errechneten Bildungsenthalpien betragen ΔH°298(WF6, gas) -411.7 ± 0.5 kcal Mol-1 und ΔH°298(WF5, fest) -346.1 ± +2.6-1.0 kcal Mol1.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 97-103 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Inorganic Small Ring Compounds, III Cyclic Silyl-alkylidene PhosphoranesA simple method has been deviced for the synthesis of silyl-substituted alkylidene phosphoranes of the type F. Two members of this series, [(CH3)3PCSi(CH3)2]2 (1) and [( PCSi(CH3)2]2 (2), were prepared from methylene trimethyl and methylene tri-n-butyl phosphorane, resp., and dimethyl dichlorsilane and characterized by means of chemical analysis and n. m. r. spectroscopy. The pathway of the reactions is discussed and a possible mechanism confirmed by an independent preparation of the most likely intermediates. Among these the difunctional open-chain ylid 4, (CH3)3P= CH=Si(CH3)2=CH = P(CH3)3, is of special interest.
    Notes: Ein einfaches Darstellungsverfahren ermöglicht die Synthese von Silyl-alkylidenphosphoranen mit viergliedrigem Ringsystem des Typs F. Zwei Vertreter dieser Reihe, [(CH3)3PCSi(CH3)2]2 (1) und [(n-C4H9)3PCSi(CH3)2]2 (2), wurden aus Trimethyl-methylen- bzw. Tri-n-butyl-methylen-phosphoran und Dimethyldichlorsilan in guten Ausbeuten erstmals hergestellt und analytisch und NMR-spektroskopisch charakterisiert. Der Reaktionsablauf der Synthese wird diskutiert und durch die getrennte Darstellung möglicher Zwischenprodukte belegt. Unter letzteren ist das offenkettige difunktionelle Ylid 4, (CH3)3P=CH  -  Si(CH3)2  -  CH - P-(CH3)3, von Bedeutung.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 147-155 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterosubstituted Fulvenes, V 6,6-Diaminofulvenes with Electronegative Substituents in the 5-Membered RingCondensation of tetramethyl chloroformamidinium chloride (5) with methoxycarbonyl-, bis(methoxycarbonyl)-, and cyanocyclopentadienyl salts leads to the correspondingly substituted 6,6-bis(dimethylamino)fulvenes 6, 7 and 8. Vilsmeier formylation of 6,6-bis(dimethyl-amino)fulvene yields the diformyl derivatives 9 and 11. Structure elucidation of the fulvenes obtained is based on spektroscopic data; the temperature dependence of the n.m.r. spectra is discussed.
    Notes: Tetramethyl-chlorformamidinium-chlorid (5) bildet mit Methoxycarbonyl-, Bis-methoxy-carbonyl- und Cyan-cyclopentadienylsalzen die im 5-Ring entsprechend substituierten 6.6-Bis-dimethylamino-fulvene 6, 7 und 8; Vilsmeier-Formylierung des 6.6-Bis-dimethylamino-fulvens liefert zwei Diformyl-Derivate 9 und 11. Die Strukturzuordnung der erhaltenen Fulvene erfolgt spektroskopisch; die Temperaturabhängigkeit der NMR-Spektren wird diskutiert.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 205-209 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Compounds with Urotropin Structure, XLVI Synthesis of the 6-Thia-l,3-diazaadamantane Ring System.A synthesis of the hitherto unknown 6-thia-l,3-diazaadamantane ring system starting from N-benzenesulfonyl-diallylamine (1), is described. The first stage of the synthesis is the sulfurdichloride addition to 1, resulting in Nbenzenesulfonyl-2,6-bis(chloromethyl)thiomorpho-line (2).2 was converted with alkali into N-benzenesulfonyl-2,6-dimethylenethiomorpholine (6) and subsequently oxidized to the sulfone 7. Addition of benzylamine followed by removal of the benzyl and the benzenesulfonyl groups yielded 9-thia-3,7-diazabicyclo[3.3.l]nonane 9,9-dioxide (11), which reacted with formaldehyde to produce 6-thia-l,3-diazaadamantane 6,6-di-oxide (12).
    Notes: Ausgehend von Benzolsulfonsäure-diallylamid (1) wird das bisher noch unbekannte 6-Thia-1.3-diaza-adamantan-Ringsystem synthetisiert, wobei im ersten Schritt die Schwefeldichlorid-Addition an 1 zu 4-Benzolsulfonyl-2.6-bis-chlormethyl-thiomorpholin (2) erfolgt. 2 wurde mit Alkali in 4-Benzolsulfonyl-2.6-dimethylen-thiomorpholin (6) und durch anschließende Oxydation in das Sulfon 7 übergeführt. Benzylamin-Addition an 7 und anschließende Abspaltung des Benzyl- und Benzolsulfonyl-Restes führte zum 9-Thia-3.7-diaza-bicyclo[3.3.1]-nonan-9.9-dioxid (11), das mit Formaldehyd das 6-Thia-s-l.3-diaza-adamantan-6.6-dioxid (12) lieferte.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Orthoamides, XII: Synthesis of Acyl Isocyanate O,N- or -N,N-Acetals from Amide Acetals or from an Aminal tert-Butylester and N-Halogencarbonamides, Halogen Ureas and N-ChlorourethanesDimethylformamide dialkylacetals (2) and aminal-tert-butylester 5 [bis(dimethylamino)-tert-butoxymethane] react with N-halogen carboxylic acid amides, halogen ureas and N-chlorourethanes to give acyl isocyanate-O,N -or -N,N-acetals (isoureas 3 or guanidines 6, respectively).
    Notes: Dimethylformamid-dialkylacetale (2) und Aminal-tert.-butylester 5 (Bis-dimethylamino-tert.-butyloxy-methan) bilden mit N-Halogen-carbonsäureamiden, Halogenharnstoffen und N-Chlor-urethan Acylisocyanat-O.N- bzw. -N.N-acetale (Isoharnstoffe 3 bzw. Guanidine 6).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 256-264 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Orthoamides, XIII Studies on the Mechanism of Electrophilic Substitution of the Formyl-H Atom in Ortho Formic Acid AmidesOrtho formic acid amides and N-halogen carboxylic acid amides, halogen ureas or N-chloro urethanes primarily react to give adducts; these form ylides in the presence of bases. The ylides react by an intramolecular SE1- or SNi-mechanism to give O,N-acetals of the corresponding acyl isocyanates (isoureas).
    Notes: Bei der Umsetzung von Orthoamiden mit N-Halogen-carbonsäureamiden, -harnstoffen und N-Chlor-urethan wurden Primär-Addukte nachgewiesen. Diese bilden in Gegenwart von Basen Ylide, welche über einen intramolekularen SE1- oder SNi-Mechanismus C-N-Knüpfung eingehen unter Bildung von O.N-Acetalen der entsprechenden Acylisocyanate (Isoharnstoffe).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 281-288 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Boron Azides, X Aminoazidoboranes and AlkoxyazidoboranesThe bis(dialkylamino)azidoboranes l a and 1b, the dialkylaminodiazidoboranes 2a and 2 b, diethylaminoazidophenylborane (3), and the dialkoxyazidoboranes 4 a and 4 b are formed from chloroboranes, chlorine being substituted by the N3-group with LiN3 or Bu3SiN3, respectively, as substitution agents. The monoazidoboranes 1, 3, and 4 are decomposed in a kinetically controlled manner at a noticeable rate only beyond 250° C; hydrolysis of the polymeric material gives the amines Et2NNH2 (from 1b), PhNH2 (from 3) and CH3ONH2 (from 4 a), respectively, indicating a rearrangement process during the thermolysis. The saltlike compounds (NH4N4 and (Et2NH2)N3, respectively, are the main products from the decomposition of the diazidoboranes 2a and 2b at 210°. The thermal decomposition of la in cyclohexene yields under participation of the solvent the diazadiborete derivative 6. From the photolytic decomposition of 1a and 1b, respectively, trisaminoboranes (as dismutation products) and the tetraaminodiazadiboretes 10 a and 10 b (as rearrangement products) are isolated.
    Notes: Die Bis(dialkylamino)azidoborane l a und l b, die Dialkylaminodiazidoborane 2 a und 2 b, Diäthylaminoazidophenylboran (3) und die Dialkoxyazidoborane 4 a und 4 b erhält man aus den entsprechenden Chlorboranen durch Azidierung mit LiN3 bzw. (im Falle von 4a) mit Bu3SiN3. Die Monoazidoborane 1, 3 und 4 zerfallen in kinetisch kontrollierbarer Weise mit nennenswerter Geschwindigkeit erst oberhalb 250°; neben N2 erhält man harzige Produkte, aus denen sich durch Verseifung die aus einer Umlagerungsreaktion hervorgegangenen Amine Ät2NNH2 (aus l b), PhNH2 (aus 3) bzw. CH3ONH2 (aus 4a) freimachen lassen. Der thermische Zerfall der Diazidoborane 2a und 2b bei 210° liefert neben N2 die salzartigen Azide (NH4)N3 bzw. (Nät2H2)N3. Der thermische Zerfall von l a in Cyclohexen führt unter Beteiligung des Lösungsmittels zum Diazadiboret-Derivat 6. Tetraaminodiazadiborete 10 a und 10 b sind neben Trisaminoboranen die Hauptprodukte des photolytischen Zerfalls von l a und l b.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wir berichteten vor einiger Zeit über die Pyrolyse von Silbertetrafluorphthalat (1) und äußerten die Vermutung, daß als Hauptprodukt isolierte Octafluorbiphenylen seine Bildung dem intermediären Auftreten des Tetrafluorbenz-ins verdankte. Um diese Vermutung zu bestätigen, wurde die Pyrolyse von 1 in Gegenwart eines potentiellen Benz-in-Abfängers durchgeführt. In Anlehnung an McNelis setzten wir dafür Tetraphenylcyclopentadienon (Tetracyclon) (2) ein.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 322-324 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 788-798 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Method for Synthesis of Peptides: Activation of the Carboxyl Group with Dicyclohexylcarbodiimide using 1-hydroxybenzotriazoles as Additives1-Hydroxybenzotriazole and a number of substituted 1-Hydroxybenzotriazoles are suitable additives in the synthesis of peptides using the dicyclohexylcarbodiimide method1). The glc-racemisation test described by Weygand and coworkers2) was used to determine the influence of these additives on the racemisation during peptide synthesis. The newly employed additives decrease racemisation, prohibit the formation of N-acylurea and afford peptides in excellent yield and a high state of purity.
    Notes: 1-Hydroxy-benzotriazol sowie verschiedene kernsubstituierte 1-Hydroxy-benzotriazole eignen sich als Zusätze bei der Dicyclohexylcarbodiimid-Methode zur Synthese von Peptiden. Ihr Einfluß auf die Racemisierung bei Peptidsynthesen wurde unter Anwendung des gaschromatographischen Racemisierungstests von Weygand u. Mitarbb.2) untersucht. Die neuen Zusätze senken die Racemisierung, verhindern die N-Acyl-harnstoffbildung und führen in hoher Ausbeute zu sehr reinen Peptiden.
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 426-439 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Stereochemistry of Sigmatropic 1,5-Hydrogen ShiftsAt 250° (S)-cis,trans-3-methyl-7-deutero-octa-4,6-diene (5) rearranges by a non-catalysed first order reaction to a mixture of (R)-trans,cis-3-methyl-7-deutero-octa-3,5-diene (3) and (S)-cis,cis-3-methyl-7-deutero-octa-3,5-diene (4). Therefore the sigmatropic 1,5-hydrogen shift proceeds in this system preferentially by way of a suprafacial transition state, which is at least 8 kcal/mol lower in energy than the antarafacial one.
    Notes: (S)-cis,trans-3-Methyl-7-deutero-octadien-(4.6) (5) lagert sich bei 250° in einer nichtkatalysierten Reaktion erster Ordnung in ein Gemisch aus (R)-trans,cis-3-Methyl-7-deutero-octadien-(3.5) (3) und (S)-cis,cis-3-Methyl-7-deutero-octadien-(3.5) (4) um. In diesem System durchläuft die sigmatrope 1.5-Wasserstoffverschiebung damit bevorzugt einen suprafacialen Übergangszustand, der um mindestens 8 kcal/Mol gegenüber dem antarafacialen Übergangszustand begünstigt ist.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 855-862 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Catalytic Hydroalumination of 1,5-HexadieneThe hydroalumination of 1,5-hexadiene normally yields (cyclopentylmethyl)dialkylaluminium instead of the expected dimetallated hexane derivative. Titanium tetrabutoxide catalyses the reaction and favours the formation of the dimetallated product. - When the reaction is carried out in the absence of a catalyst but in the presence of electron donors such as ethers or tertiary amines, the two-fold hydroaluminated product is also formed exclusively. In such cases the reaction velocity is, however, drastically reduced. Titanium tetrabutoxide has now been found to act as an extraordinarily effective catalyst for this reaction, even in the presence of complex-forming agents. Certain amines or tetrahydrothiophene even intensify the catalytic activity of the titanium (IV) compound.
    Notes: Die Hydroaluminierung von Hexadien-(1.5) führt normalerweise nicht zu dem erwarteten dimetallierten Hexanderivat, sondern zum Cyclopentylmethyl-dialkyl-aluminium. Titantetrabutylat katalysiert die Reaktion und lenkt sie in Richtung des dimetallierten Produktes. Bei Durchführung der Reaktion ohne Katalysator, jedoch in Gegenwart von Elektronendonatoren wie Äthern oder tertiären Aminen wird ebenfalls ausschließlich das zweifach hydroaluminierte Reaktionsprodukt gebildet. Die Reaktionsgeschwindigkeit wird dabei allerdings drastisch vermindert. Titantetrabutylat katalysiert nun die Reaktion auch bei Anwesenheit der Komplexbildner außerordentlich wirksam. Durch einige tertiäre Amine oder auch durch Tetrahydrothiophen wird die katalytische Aktivität der Titan (IV)-Verbindung sogar noch verstärkt.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 486-495 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hydrazine Reactions, X Studies on Inversion-isomeric 1-Chloro-and 1-Aminoaziridines. Dependence of the 1H-C-14N-Coupling on the Konformation of the free Electron PairThe 1H-C-14N coupling depends on the conformation of the nitrogen lone-pair electrons. In 1-chloroaziridine for protons „cis“ to the nitrogen lone-pair electrons great values were found and for „trans“ protons smaller ones. The AA' BB'-system in the n.m.r. spectrum of 1-chloroaziridine is unsymmetrical. Irradiating of 14N frequency gives decoupling of 14N from other nuclei and the spectrum becomes symmetrical. In 1-amino-2-phenylaziridine the isomer with phenyl and amino group in „trans“ position is favoured. The variation of chemical shift in benzene solution of 1-amino- and 1-chloroaziridines are discussed.
    Notes: Die 1H-C-14N-Kopplung ist von der Konformation des freien Elektronenpaares abhängig und besitzt im 1-Chlor-aziridin für zum freien Elektronenpaar„cis“-ständige Protonen große, für „trans“-ständige kleine Werte. Das AA' BB'-System des NMR-Spektrums von 1-Chloraziridin ist daher unsymmetrisch und zeigt erst beim Einstrahlen der 14N-Frequenz infolge Spinentkopplung Symmetrie. 1-Amino-2-phenyl-aziridin liegt bevorzugt als das Inversionsisomere vor, in dem Phenyl- und Aminogruppe „trans“ zueinander stehen. Die Signalverschiebungen von 1-Amino-und 1-Chlor-aziridinen in Benzol werden diskutiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 534-538 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Structure of SphaerophysineSphaerophysine-formerly described as 1 or 2- is shown by n.m.r. and mass spectrometry to have structure 3 (N-(4-aminobutyl)-N-(3-methyl-2-butenyl)-guanidine). Dihydro-3 (7) has been synthesised.
    Notes: Sphaerophysin wurde bisher als 1-Isopentenylamino-4-guanidino-butan 1 oder 2 angesehen. Wir zeigen anhand von NMR- und Massenspektren sowie durch Synthese der Dihydro-verbindung, daß es die Struktur 3 eines N[4-Amino-butyl]-N-[3-methyl-buten-(2)-yl]-guanidins hat.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 564-572 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterosubstituted Acetylenes, XXV Chain-Extension of Aldehydes and Ketones by two Carbon Atoms with Ynamines: Synthesis of Substituted AcrylamidesThe addition of ynamines to carbonyl groups, especially of aldehydes and ketones, leads to derivatives of acrylamides by reduction of which with lithiumaluminiumhydride and hydrogenation amines are available. The stereochemistry of the condensation has been investigated. cis- acrylamides are stereospecifically obtained by a kinetically controlled reaction from aldehydes.
    Notes: Die Addition von Inaminen an Carbonylverbindungen, insbesondere Aldehyde und Ketone. Führt zu Acrylamidderivaten, aus denen mit Lithiumaluminiumhydrid und durch Hydrierung Amine erhältlich sind. Die Stereochemie der Addition wurde untersucht: Aus Aldehyden entsteht kinetisch gesteuert und stereospezifisch das cis-Acrylamid.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 648-651 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 659-662 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Hydrocarbons by Cycli-alkylation, IV. Cycli-alkylations of Benzene and Partially Hydrogenated Polycyclic Aromatic Hydrocarbons with 1.2-Bis(bromomethyl)cyclohexaneThe reactions of benzene and partially hydrogenated aromatic hydrocarbons such as tetrahydronaphthalene and symm. octahydrophenanthrene with a mixture of cis- and trans 1.2-Bis (bromomethyl)cyclohexane in the presence of aluminiumchloride lead to the partially hydrogenated polycyclic hydrocarbons 2-6; the dehydrogenation with Pd/C yields the corresponding aromatic compounds.
    Notes: Die Reaktionen von Benzol and teilhydrierten Aromaten, wie Tetrahydronaphthalin und symm. Octahydrophenanthren, mit einem Gemisch aus cis- und trans-1.2-Bis-brommethyl-cyclohexan in Gegenwart von Aluminiumchlorid führen zu den partiell hydrierten polycyclischen Kohlenwasserstoffen 2-6, deren Dehydrierung mit Pd/C die entsprechenden Aromaten ergibt.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...