NORMAL-MODES OF P-AMINOBENZONITRITE AND P-DIMETHYLAMINOBENZONITRILE -VIBRATIONAL-SPECTRA AND PM3 CALCULATIONS WITH A MODIFIED SCALING PROCEDURE

In addition to IR spectra, polarized Raman spectra of p-aminobenzonitr ile and p-dimethylarninobenzonitrile in acetonitrile solution were rec orded with different excitation wavelengths, Normal mode coordinates w ere calculated using a modified PM3 program package. Instead of only s caling the calculated wavenumbers of the resulting normal modes, a sca ling factor was introduced into the force field. Since the normal coor dinate pictures of several modes change owing to different mixing of l ocal modes, a modified assignment for several modes is proposed. (C) 1 997 by John Wiley & Sons, Ltd.