IR-SPECTRAL STUDY OF 4'-SUBSTITUTED PHENYLTHIOLBENZOATES IN SOLUTION

A doublet structure of the C=O stretching band in the IR-spectra of 4' -methoxy-, 4'-methyl- and 4'-cyanophenylthiolbenzoate is proved. The s olvatochromic effect on the intensities of both components suggests an equilibrium between two conformers with different dihedral angle dete rmined by the plains of the benzene rings. The choice of the studied c ompounds is influenced by the fact that they are structural fragments of liquid crystals. The characterization of their rotameric preference in solution provides additional information about the influence of th e terminal groups on the conformational mobility of the phenylthiolben zoate skeleton as well as on the polarizability of the molecule.