Crown-containing Spirooxazines and Spiropyrans

Methods for the synthesis of new spironaphthooxazines containing an aza-15-crown-5 fragment in two different positions (5′ and 9′) were developed. The spectral and photochemical properties of these compounds suggest that two competitive complexation processes occur with alkaline-earth or rare-earth metal cations differing in efficiency and selectivity. A metal cation occupies the optimum position in the crown-ether cavity with respect to the donor oxygen atom of the merocyanine form of the dye and thus can affect more strongly its spectral and photochemical properties than in the case of intermolecular interaction.