Novel polymethine dyes derived from aminals and aminal-acetals of conjugated ω-dimethylaminoaldehydes

1.	A series of tetracyanopolymethines has been synthesized by condensation of aminals and aminal-acetals of conjugated -dimethylaminoaldehydes with malonodinitrile.
2.	These tetracyanopolymethines can be used as the anionic components in cation-anion cyanine dyes.
3.	The electronic absorption spectra of these newly synthesized dyes were studied in both polar and nonpolar solvents. Specific cation-anion interaction and complex formation has been shown to occur in several of these cation-anion dyes in nonpolar solvents.

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 92–98, January, 1989.