Dimethylidynemerocyaninocyanines — substituted benzimidazole derivatives

Dimethylidynemerocyaninocyanines — substituted benzimidazole derivatives — were synthesized. A decrease in the basicity of the benzimidazole ring with intensification of the electronegative properties of the substituent gives rise to a small (up to 10 nm) heightening of the color of the dyes obtained. The latter are rather effective spectral sensitizers of silver halide photographic emulsions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 815–818, June, 1984.