Effect of Non-Zero Extinction Coefficient on Abstraction–recombination Rate Ratios in Photochemical Systems

The data of Marjury and Steacie on the photolysis of acetone and acetone-d 6 in the presence of H 2 and D 2 respectively have been re-analyzed in terms of the integrated rate equations. It is concluded that only part of the discrepancy between the results for the methyl and hydrogen reaction can be accounted for in this way.In an appendix, it is shown that for high extinction coefficients, the integrated rate expression reaches a limit which may sometimes be attainable experimentally without undue complication from diffusion effects.