Pyrylocyanines. 33. Pyrylocarbocyanines with bridge groups in the chromophore

Salts of 4,4-tetra-, penta-, and hexamethylene-bis-(2,6-diphenylpyrylium) and -thiopyrylium were synthesized and used as the basis for producing trimethylcyanines with ethylene, tri- and tetramethylene bridge groups in the chromophore. Factors influencing the color of these dyes were analyzed. The bis-pyrylium salts were converted to derivatives of pyridine, N-methyl- and N-phenylpyridinium. The structure of the compounds obtained was confirmed by the data of electron spectroscopy and PMR spectroscopy.