Infrared Spectra of Benzoyl Halides and their Substituted Derivatives.

Abstract

Infrared absorptions of benzoyl halides and their ortho-, meta-, and para-substituted derivatives were examined and following conclusions were drawn. 1) Absorptions of these compounds in the C=O region are mostly split into two. This is due to the Fermi resonance of the C=O stretching vibration and overtone of C-X (X=halogen atom) stretching vibration. 2) There are two strong absorptions in the region of 1240∼1140 cm^-1. The absorption in the highere frequency is that of [chemical formula] stretching vibration and that in the lower frequency is the absorption of ring CH in-plane bending vibration. 3) In majority of compounds with the exception of meta-substituted derivatives, the -C-X (X=halogen atom) stretching vibration is the strongest absorption and is the most characteristic. 4) The summation bands are similar to those of benzoic acid esters.