VIBRATIONAL-RELAXATION IN LIQUID PHENYLACETYLENE - 1

Raman and IR spectra of phenylacetylene dissolved in methylcyclohexane and acetonitrile have been recorded, The IR line widths and Raman Iso tropic line widths of totally symmetric A(1) vibrations of phenylacety lene-the stretching mode of the ethynyl group C=C (v(S)(C=C)), the phe nyl ring in-plane stretching (v(8a)), the C-phenyl group stretching (v (S)(C-Ph)), and the phenyl ring breathing (mixed with trigonal vibrati on) (v(12))-have been recorded, The spectra have been measured as a fu nction of concentration at room temperature. Theoretical models of vib rational dephasing have been tested and compared with experiment.