Normal coordinate analysis and infrared band intensities of nitromethane and nitromethane-D3

Abstract EN

Laser Raman and Infrared (60-3500 cm"') spectra of nitromethane and nitromethane-dj, in their standard states are discussed.

Complete and unambiguous assignment of all observed vibrational bands of nitromethane are made on the basis of the results of the calculated normal modes, isotope frequency shifts and calculated quantum values of infrared band intensities.

Infrared band intensities are calculated using INDO semi-empirical quantum chemical method.

The torsion mode of vibration of the CH3 group was detected at 144 cm "'.

This indicates the presence of a sort of association between nitromethane molecules in the liquid state.

A set of force constants for nitromethane is developed and refined using the least square fit method.