The photochromic reactions spiropyran-merocyanine in polymeric matrices have been analysed with respect to their distributions of rates in order to understand the matrix effects on the kinetics in the transition range from a static to fluid environment. Employing the technique of part I we find a static matrix situation only below the Vogel-Fulcher temperature TVF of the polymer where different species are identified in terms of distinct but distributed decolouration rates. Above the glass transition TG the ensemble averaged reaction approaches an exponential decay pattern, due to the fluctuations of site specific barriers and exchange mechanisms among the set of merocyanine isomers.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry