A Photochemical Procedure for Determining Reaction Quantum Efficiencies in Systems with Multicomponent Inner Filter Absorbances

A kinetic procedure for measuring the photochemical quantum efficiencies of reactions in which several components have overlapping absorbances is fully described. This method has been found to be particularly suitable for photochemical determinations where inner filter effects are substantial, such as those typically observed in the ligand substitution and intermolecular C-H/Si-H bond activation mechanisms of metal complexes. The quantitative measurement of the Si-H bond activation photochemistry of (η(5)-C(5)H(5))Rh(CO)(2) in triethylsilane solution is demonstrated in detail, although the procedure has widespread application in photochemistry.