* Chemical Dept., M.V. Lomonosov Moscow State University, Vorob'evy gory, 119899, Moscow, Russia (e-mail: druzh@light.chem.msu.su)

^# N.N. Semenov Institute of Chemical Physics, Russian Academy of Science, Novatorov 7a, 117421, Moscow, Russia

ABSTRACT. The absorption and fluorescence spectra of complexes of styryl dye (1) with lithium, sodium, magnesium, and calcium cations in MeCN have been investigated. The addition of Li, Na, Mg, and Ca perchlorates to the solution of dye 1 in acetonitrile results in the significant (up to 5900 cm^-1) shortwavelength shift of absorption spectrum and a small (about 200 cm^-1) shortwavelength shift of fluorescence spectrum. The recoordination reaction in metal complexes of 1 takes place by intramolecular mechanism. The fluorescence quantum yield of 1Li⁺, 1Na⁺, and 1Ca²⁺ is approximately two times higher than that for 1. It was supposed that coordinates predominantly with oxygen atoms of macrocycle and, hence, influences weakly on macrocycle nitrogen atom conjugated with a molecule p-system.