Raman light scattering by compositions of highly-ordered trans-nanopolyacetylene

Compositions of highly ordered trans-nanopolyacetylene (trans-NPA) were prepared in the form of solutions, films and plates. They are characterized by the high stability and vibrational structure of the cis and trans bands in UV-Vis absorption spectra. There are five basic features that distinguish the Raman scattering by the trans-NPA compositions from the Raman scattering by the standard awns-PA modifications. (I) Extremely low intensity of fluorescence at excitation in visual region. (2) The weak frequency dispersion of polyene C=C and C-C stretching bands, which is evidence for the narrow length distribution of conjugation chains. (3) The occurrence of long sequences of overtones and combination bands in room-temperature resonance and off-resonance Raman spectra. (4) High intensities of the anti-Stokes lines of the fundamentals vl and nu(3) of the polyene chain. (5) Extremely high intensities of the nu(1) and nu(3) fundamentals of the polyene chain.