REDUCED LD SPECTRA OF BENZONITRILE, P-NITROBENZONITRILE, M-NITROBENZONITRILE AND O-NITROBENZONITRILE IN NEMATIC SOLUTIONS

Reduced LD spectra of benzonitrile, p-, m- and o-nitrobenzonitrile wer e recorded in the nematic liquid crystal ZLI-1695 (Merck) according to the ''stepwise reduction'' method of Thulstrup and Eggers[1]. It was shown that the in-plane vibrations of the nitrogroup and the out-of-pl ane benzene ring vibrations of the low symmetric o- and m-compound ari se from mutually orthogonal vibrational transition moments that can se rve for fixing a Cartesian coordinate frame to which all other transit ions moment can be referred.