Polymethine dyes - 4-substituted furo [2,3-b]- and selenopheno[2,3-b]pyridine derivatives

Polymethine dyes that are 4-substituted furo2, 3-b]pyridine and selenopheno-2, 3-b] pyridine derivatives were synthesized. It was shown that replacement of the vinylene group in the benzene ring of a 4-quinoline heteroresidue in the cyanine dyes by an oxygen or selenium atom causes a greater hypsochromic shift in their absorption maxima than replacement by a sulfur atom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 56–60, January, 1976.