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  • 1
    Electronic Resource
    Electronic Resource
    Localization of N-oxide groups by means of nitrogen chemical shifts (1980)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 14 (1980), S. 305-308 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The applicability of nitrogen chemical shifts to the localization of N-oxide groups in azine ring systems is exemplified by 1,2,4-triazine systems. The average excitation energy approximation in the theory of magnetic shielding gives a good linear correlation with the nitrogen shieldings in azine N-oxides.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270140418
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  • 2
    Electronic Resource
    Electronic Resource
    Some INDO calculations of the dependence of one-bond phosphorus-phosphorus coupling upon molecular geometry (1983)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 21 (1983), S. 199-202 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some INDO parameterized SCPT calculations of 1J(P—P) and 1J(P≡P) are reported as a function of geometry. At structures corresponding to the gas-phase equilibrium configuration of diphosphine, all of the substituted diphosphines considered are predicted to have negative values of 1J(P—P). Both contact and non-contact contributions to 1J(P—P) are significant, whereas the angular variation of 1J(P—P) is mainly due to the contact term. The non-contact interactions are dominant in determining the value of 1J(P≡P).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/omr.1270210312
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  • 3
    Electronic Resource
    Electronic Resource
    Some quantum chemical aspects of solvent effects on NMR parameters (1981)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 15 (1981), S. 111-130 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The non-bonded interactions which occur between solute and solvent molecules are discussed and the various models which describe the interactions are presented. The models are employed, within a quantum chemical framework, to estimate the extent of medium effects on chemical shifts and spin-spin couplings. Comparison between the calculated and available experimental data is provided for some first row nuclei.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270150202
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  • 4
    Electronic Resource
    Electronic Resource
    G. C. Levy (Editor). ACS symposium series vol. 191 - NMR spectroscopy: New methods and applications. ACS, Washington, DC, 1982, 398+ix pp. US $59.95 (1983)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 21 (1983), S. 463-464 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/omr.1270210715
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  • 5
    Electronic Resource
    Electronic Resource
    A 15N NMR investigation of some azolopyridines (1984)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 22 (1984), S. 209-214 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 15N NMR chemical shift data are presented for 14 azolopyridines, together with the results of INDO/S-SOS calculations of nitrogen shieldings. Previous 14N NMR results for some of these compounds are reinterpreted. The 14N data and their assignments are shown to be reliable for the indolizine nitrogen atom from arguments based on relative line widths. The pyridine-type nitrogens are more reliably assigned from the 15N spectra combined with the results of the INDO/S-SOS calculations for individual molecules. A combination of 14N and 15N NMR spectra, together with the shielding calculations, provides a basis for unambiguous assignments of all the various nitrogen environments considered.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270220403
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  • 6
    Electronic Resource
    Electronic Resource
    Substituent effects on one-bond 15N—13C couplings in N,N-dimethylanilines and nitrobenzenes. Effect of steric inhibition of conjugation (1982)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 20 (1982), S. 11-15 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1J(15N13C) values for a series of ring-substituted N,N-dimethylaniline-15N derivatives and a series of nitrobenzene-15N derivatives were measured from the 13C spectra. In the nitrobenzenes, small changes in 1J(15N13C) are attributed to the inductive effect of the substituents, since steric inhibition of conjugation has little effect on the magnitude of the coupling. In contrast, steric inhibition of nitrogen lone-pair delocalization in N,N-dimethylaniline derivatives markedly reduces the value of 1J(15N13C). Theoretical calculations of 1J(15N13C) values for the two series of compounds were made using standard INDO parameters and a ‘sum-over-states’ perturbation approach. Fair agreement between the calculated and experimental values is found.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270200104
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  • 7
    Electronic Resource
    Electronic Resource
    Some INDO calculations of 1J(PC) and 1J(PF) values (1983)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 21 (1983), S. 125-129 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: INDO parameterized calculations, employing phosphorus s, p and d valence orbitals, are reported for values of 1J(PC) and 1J(PF) relating to phosphorus in formal tri- and pentavalent states. The 1J(PC), interactions are mainly controlled by the contact term. Thus, trivalent phosphorus compounds have negative values for 1J(PC), whereas those for pentavalent phosphorus are positive due to the s lone-pair effect. The inclusion of phosphorus 3d orbitals is shown to be important for an understanding of the processes contributing to 1J(PF) interactions. 1J(PF) values are shown to be negative for both tri- and pentavalent phosphorus compounds. The contact and orbital interactions are significant for the trivalent phosphorus molecules, whereas in the pentavalent phosphorus case 1J(PF) is dominated by the orbital term.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/omr.1270210210
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  • 8
    Electronic Resource
    Electronic Resource
    M. Gerloch. Magnetism and ligand-field analysis. Cambridge University Press, 1984. 593 pp. £55.00, $110.00 (1984)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 22 (1984), S. 476-476 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270220719
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  • 9
    Electronic Resource
    Electronic Resource
    Calculation of some fluorine nuclear screening constants (1977)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 10 (1977), S. 70-74 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 19F screening constants and their anisotropies have been calculated for 50 fluorine molecular environments. The calculations have been performed within a framework in which gauge-dependent atomic orbitals are used in the molecular orbital description. Calculations employing both INDO and CNDO/S standard parameterizations are reported. The molecules considered include simple binary fluorides and fluorocarbons. Both sets of calculations provide reasonable accounts of the 19F screening data for the binary fluorides. The presence of electric field effects in the aliphatic fluorocarbons are not accounted for by the present calculations. In the conjugated fluorocarbons the gross 19F chemical shift trend is reproduced except for ortho fluorines where electric field contributions are significant. The most highly screened component of σ is calculated to lie along the C—F bond of various fluorobenzenes but perpendicular to the plane of 4,4′-difluorobiphenyl, in agreement with experiment.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270100118
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  • 10
    Electronic Resource
    Electronic Resource
    Calculation of the nitrogen screening constants of some N-heterocycles (1978)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 11 (1978), S. 27-30 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Absolute nitrogen screening constants and chemical shifts of some N-heterocycles are calculated within the CNDO/S level of approximation to Pople's model. Satisfactory agreement between calculated and observed nitrogen chemical shifts is obtained in most cases. The application of the results to the study of tautomeric equilibria is discussed. ‘Pyridine-type’ nitrogen chemical shifts are dominated by n → π* transitions together with significant contributions from π → σ* and σ → π* transitions whereas the latter two are the dominant ones for ‘pyrrole-type’ nitrogen nuclei.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270110107
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