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Studies of the substituent effect in aromatic systems by 35 Cl‐NQR. Chloroacetanilides Cl x C 6 H 5−x NHCOCH 3−y Cl y
Author(s) -
Pies W.,
Rager H.,
Weiss Alarich
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.1270030202
Subject(s) - substituent , acetanilide , chemistry , benzene , nuclear quadrupole resonance , chlorobenzene , inductive effect , chlorine atom , steric effects , spectral line , ring (chemistry) , crystallography , medicinal chemistry , stereochemistry , nuclear magnetic resonance , organic chemistry , physics , catalysis , astronomy
The 35 Cl‐NQR spectra of 45 chlorosubsitituted acetanilides, Cl x C 6 H 5−x NHCOCH 3−y Cl y , were investigated and the temperature dependence of some spectra, especially of monochloroacetic acid derivatives, was measured. A preliminary assignment of the NQR frequencies is given. A correlation between NQR frequencies and substituent parameters permits the study of the substituent effect of the acetamido group, NHCOCH 3−y Cl y . The chloro‐substitution in the side chain of the acetanilides seems to have no noticeable influence on the 35 Cl‐NQR frequencies of the chlorine atoms at the benzene ring. The NQR frequencies of the chlorine atoms in the chloroacetamido group are, on the other hand, insensitive to substitutions at the benzene nucleus. The possibility of steric influences on the NQR spectrum of ortho ‐chloro‐substituted acetanilides is discussed. The investigation further confirms that a crystal field effect of about ±500 kHz must be considered in the interpretation of NQR spectra of chlorobenzene derivatives.