Temperature Dependence of Internal Torsional Frequencies in 3,4-Dichloro Nitrobenzene and 4-Chloro 2 Nitrophenol Using NQR Data

Abstract

The temperature variation of the nuclear quadrupole resonance frequency in the two compounds 3,4-dichloro nitrobenzene and 4-chloro 2 nitrophenol were analyzed in the light of the Kushida and Brown models. The internal torsional frequencies at each temperature was calculated using Bayer’s model with Tatsuzaki correction under a two-mode approximation to obtain the temperature variation of the torsional frequencies in both compounds. The torsional frequencies are seen to lie between 25 cm i1 and 85 cm i1 in the first compound and between 30 cm i1 and 42 cm i1 in the case of the second compound. The temperature dependence of the torsional frequencies is linear above 150 K in the first compound and is linear throughout the range 77 K to 350 K in the second. The smaller temperature dependence in the second compound may be the eect of hydrogen bonding in this compound. PACS numbers: 76.60 Gv