PHOTOKINETICS UNDER CONTINUOUS IRRADIATION

This paper show that both direct and reverse quantum yields, the UV/vi sible spectra of unstable open forms and the quantum yields of photode gradation can be extracted by dynamic modelling and inverse treatment of the plots of Abs vs time under continuous irradiation at various se lected wavelengths. The basic concepts underlying this dynamic approac h are described here using experimental examples in liquid solution. T his method was used for a quantitative study of the photochromic spiro oxazines. Contrary to fast methods (flash-photolysis), kinetic studies under continuous irradiation are performed under similar conditions t o those encountered in natural or industrial environments.