Photophysics and kinetics of naphthopyran derivatives, part 1:: General analytical solutions for the kinetics of AB(k,φ) and ABC(k,φ) systems

A new formalism allowing solution of the differential equations for kinetic systems comprising three species (ABC) linked by first-order thermal and/or photochemical reactions is proposed. The approach is developed specifically with photochromic materials in mind, but the formalism developed is shown to be applicable to a variety of kinetic systems irradiated with monochromatic light where the photokinetic factor (F) is constant, (C) 2005 Wiley Periodicals, Inc.