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Rotational isomerism—XII Rotamer energies and 3 J HF and 4 J HH couplings in 1‐chloro‐2‐bromo‐2‐fluoropropane ( 1 )
Author(s) -
Abraham R. J.,
Oliver W. L.
Publication year - 1971
Publication title -
organic magnetic resonance
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0030-4921
DOI - 10.1002/mrc.1270030612
Subject(s) - conformational isomerism , electronegativity , substituent , chemistry , solvent , stereochemistry , physics , molecule , crystallography , computational chemistry , organic chemistry
The complete analysis of the NMR spectrum of CH 2 Cl.CFBr.CH 3 in CCl 4 and acetone is given. The long range 4 J HH couplings in this molecule differ considerably and surprisingly are both positive. An analysis of the solvent dependence of the couplings enables the rotamer couplings and energies to be obtained. The rotamer energies and their variation with solvent are in accord with quantitative predictions and results from similar halogenated ethanes. The values of the 4 J HH couplings can be rationalised in terms of substituent electronegativity effects.