The polymerization of acetylene on a catalytic system, composed of binuclear
rhenium complexes and reducing agent, in solution of saturated polymers
leads to soluble compositions containing nanoparticles of polyacetylene
with low content of conformational and chemical defects.
Studying the structure of polyacetylene obtained in different polymeric
matrices indicates that the compositions of polyacetylene with poly(vinyl
butiral) are of greatest interest for theory and practice. In this report,
fundamental regularities of Raman scattering by the trans-nanopolyacetylene
(trans-NPA) compositions are reported. The results make it possible to
formulate four basic features that distinguish the Raman scattering by
the trans-NPA compositions from the standard trans-PA modifications.The
weak frequency dispersion of polyene C=C and C-C stretching bands, which
is evidence for the narrow length distribution of conjugation chains and
the narrow energy distribution of the lowest-lying excited states 1Bu and
2Ag in trans-NPAThe occurrence of long sequences of overtone and combination
bands in room-temperature resonance Raman spectra and the occurrence of
at least two overtones and combination band in room-temperature off-resonance
Raman spectra (785- and 1064 nm excitations) of trans-NPA compositions.
High intensities of the anti-Stokes lines of the fundumentals C=C and
C-C stretching vibrations of the polyene chain.
Extremely high intensities of the fundamentals C=C and C-C stretching
vibrations of the polyene chain. Compositions of trans-NPA could be used
for elaboration of new types of Raman lasers and security of objects and
documents against forgery.