Molecular mechanics studies of acyl halides: II. Vibrational spectra

A newly developed acyl halide molecular mechanics (MM3) force field can accurately calculate molecular geometry, usually to within experimental error. The new force field can also calculate vibrational frequencies. The acyl halides studied were formyl halides, acetyl halides, propionyl halides, n-butyryl halides, 2-methylpropionyl halides, and 2,2-dimethylpropionyl halides. The rms deviation for vibrational frequencies was 28 cm−1. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 1387–1401, 1998