Resonance Raman spectra of c i s (CH)x and (CD)x

Abstract
Resonance Raman spectra are reported for as‐grown films of the organic semiconductor polyacetylene containing up to 96% of the cis isomer. Spectra were measured for (CH)x and (CD)x at 77 K at 20 cw excitation wavelengths in the range 458 to 680 nm. Excitation profiles for the principal Raman‐active modes [at 910, 1250, and 1540 cm1 in (CH)x and at 976 and 1470 cm1 in (CD)x] and their first overtones and combinations are presented. Changes in position and shape of these cis Raman bands with changing excitation wavelengths are also presented. Competing luminescence processes following photoexcitation are examined, as are contrasting resonant features associated with the small fraction of trans isomer in these samples.