Electronic spectra of 5,6-polymethylenethiapyrylium salts and certain oxygen analogs

Electronic absorption and emission spectra of substituted 5,6-tri- and 5,6-tetramethylenethiapyrylium salts are examined to determine the influence of the degree and character of substitution of the heterocycle, the size of the condensed alicycle, the nature of the heteroatom and the counterion, and the polarity of the solvent.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 198–202, February, 1985.