Nature of electronic states and mechanism of photocoloration of oxaindanespironaphthopyrans

The nature of the electronic states was studied, and the mechanism of photocoloration is discussed for spironaphthopyrans of the oxaindane series. The life times of the T states, the quantum yields, the quenching rate constants, and the activation energies of the photocoloration are determined.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 4, pp. 495–499, July–August, 1989.The authors express their sincere gratitude to V. A. Lokshin for providing the spiropyrans.