RAMAN STUDY ON PARA-NITROANILINE - MOLECULAR-STRUCTURE IN THE MOLTEN PHASE

The Raman spectrum of pure liquid para‐nitroaniline (p‐NA) was studied between 150 and 220°C, and compared with those of the crystal and solutions. The 1270–1350 cm−1 region is the most significant. The ν NO 2s line, very weak for the solid, becomes intense in the spectrum of molten p‐NA. Except for one case, all the depolarization factors are smaller than 0.75. We then assumed that, as in the cyrstal, the molecules are gauche in the pure liquid and that the conjugation state is slightly modified, the NO2 group being more localized. In the spectra of the solutions the ν NO 2s lines are the strongest. Copyright © 1979 Heyden & Son Ltd.