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N. Sheppard

Bio: N. Sheppard is an academic researcher from University of Cambridge. The author has contributed to research in topics: Adduct & Dimethyl ether. The author has an hindex of 7, co-authored 8 publications receiving 348 citations.
Topics: Adduct, Dimethyl ether, Ether, Molecule, Hydrogen bond

Papers
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Journal ArticleDOI
TL;DR: In this paper, the infra-red spectra of ethylenediamine complexes of Pt II, Pd II, Cu II and Ni II have been compared and an assignment has been made to the fundamental vibrations of the molecules on the basis of comparison with the Spectra of molecules whose assignment is established.

100 citations

Journal ArticleDOI
TL;DR: In this paper, a comparison of the infrared spectrum of a number of complexes in which ethylene is co-coordinated to platinum and palladium is made. And a fairly complete assignment has been made of the fundamental vibration frequencies of the bonded ethylene molecule.

52 citations

Journal ArticleDOI
TL;DR: A study of the infra-red spectrum of ethyl vinyl ether in the solid, liquid, and gaseous states showed the existence of rotational isomers as discussed by the authors.

29 citations

Journal ArticleDOI
TL;DR: In this paper, a detailed analysis of the hydrogen nuclear magnetic resonance spectra of some substituted ethanes and substituted ethylenes (vinyl compounds) has yielded the magnitudes and relative signs of the interproton coupling constants.

28 citations


Cited by
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Journal ArticleDOI
P Cossee1
TL;DR: In this paper, a mechanism for the polymerization of olefins is proposed, which involves to a first approximation an electronic rearrangement and only small nuclear displacements.

817 citations

Journal ArticleDOI
TL;DR: In this paper, a metal-surface selection rule has been used in interpreting infrared spectra from molecules adsorbed on finely-divided metals, which has been shown to be applicable to the case of catalysts with supported etal catalysts.

284 citations

Journal ArticleDOI
TL;DR: In this article, the nature and types of lone-pair effects on nuclear spin coupling constants are reviewed in the context of a localized bond description of molecular electronic structure, with particular attention paid to couplings involving H, C, N, F and P nuclei, organized in a systematic manner into nine categories.
Abstract: The nature and types of lone-pair effects on nuclear spin coupling constants are reviewed in the context of a localized bond description of molecular electronic structure. Emphasis is placed on the importance of residual delocalization involving the otherwise lone-pair orbital, in terms of which the effect of an X lone-pair, when compared with an isoelectronic YH or XH+ group or with an XR group, and its orientational dependence can be interpreted. One-, two- and three-bond coupling constants are considered and the importance of lone-pair effects for configurational and conformational information is stressed and illustrated. They also serve for a better understanding of substituent inductive effects on coupling constants. A large collection of illustrative examples are presented, with particular attention paid to couplings involving H, C, N, F and P nuclei, organized in a systematic manner into nine categories. The signs of the lone-pair effects on the reduced coupling constants are found to be independent of the actual nuclei under study in the same category. This is taken as an indication that the electron lone-pairs mainly affect the Fermi contact contribution to the coupling and, accordingly, an interpretation is given in terms of simple sum-over-states models. In addition, symmetry-based relationships are established involving the sign of lone-pair effects in coupling constants between nuclei which are a different number of bonds apart.

195 citations