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The Photochemistry and Photophysics of Spiropyrans

The results of studies on the structure and nature of the electronic states of spiropyrans (SP) and the products of their photochromic reactions as well as the mechanism of the dissociation of the Cspiro–O bond and the formation of a coloured form of the SP are surveyed and analysed. Also analysed are the mechanisms of the α-dissociation and predissociation of the bond, which make it possible to explain satisfactorily the dependence of the quantum yield of the photocolouring reaction on the structure of the SP, the nature of the matrix, and temperature. The prospects for the utilisation of the photochromic SP are discussed. The bibliography includes 179 references.