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Nuclear Quadrupole Resonance and Stereochemistry I. α – Chloro ethers
Author(s) -
Ardalan Ziba,
Lucken Edwin A. C.
Publication year - 1973
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19730560530
Subject(s) - chemistry , nuclear quadrupole resonance , lone pair , chlorine , resonance (particle physics) , quadrupole , electron , oxygen atom , chlorine atom , spectral line , atom (system on chip) , crystallography , stereochemistry , nuclear magnetic resonance , atomic physics , molecule , medicinal chemistry , organic chemistry , physics , quantum mechanics , astronomy , computer science , embedded system
35 Cl nuclear quadrupole resonance spectra of cyclic α‐chloro ethers of known configuration are presented. The resonance frequencies of chlorine atoms in equatorial positions are in every case some 2.5 MHz higher than those of corresponding chlorine atoms in axial positions. Similar results are obtained for open‐chain trichloromethyl ethers and the effect is sufficiently well‐defined to distinguish between configurational isomers and establish their conformation. These results may be rationalised in terms of a model in which the lone‐pair electrons on the oxygen atom hyperconjugate with the electrons of the CCl bond.