Approximating the product spectrum and product concentrations in continuous photochemical reactions

Abstract

Several approximations to a common photochemical rate law, in which the rate is proportional to the fraction of light absorbed by the reactant chromophore, have been developed to permit the product spectrum to be determined from a sequence of spectra during irradiation that exhibit isosbestic points. The methods were tested on the photolysis of [Cr(NH₃)₆]³⁺ and [Cr(en)₃]³⁺ (en = ethylenediamine) in water, and [Fe(Et₂dtc)₃], tris(diethyldithiocarbamato)iron(III), in CHCl₃.