Vibrational analysis of mononitro substituted benzamides, benzaldehydes and toluenes - Part I. Vibrational spectra, normal coordinate analysis and transferability of force constants of nitrobenzamides, nitrobenzaldehydes and nitrotoluenes

摘要

The Raman and Fourier transform infrared (FTIR) spectra of p-, m- and o-nitrobenzamides, p-, m- and o-nitrobenzaldehydes and p-, m- and o-nitrotoluenes were recorded. Raman polarisation measurements were made for the liquid samples. A normal coordinate analysis was carried out for both in-plane and out-of-plane vibrations of these molecules using 111-parameter modified valence force field. The force constants were refined using 316 frequencies of nine molecules in an overlay least-square technique. The reliability of the force constants was tested by making a zero-order calculation for nine related molecules. Unambiguous vibrational assignments of all the fundamentals were made by using the potential energy distributions and eigen vectors. (C) 2003 Elsevier B.V. All rights reserved. [References: 39]