Photodecarboxylation of ketoprofen studied by transient absorption spectroscopy and transient grating method: Estimation of the partial molar volume of carbon dioxide

Abstract

The photoreaction of ketoprofen, a widely used nonsteroidal anti-inflammatory drug (NSAID), was intensively investigated in methanol by transient absorption spectroscopy and transient grating (TG) method. From quantitative analyses of the transient absorption and of the TG signal due to CO2, we successfully determined the partial molar volume of CO2 to be 46 ± 2 cm3 mol−1. With the partial molar volume of CO2 obtained in this work, the reaction quantum yield of photodecarboxylation of other NSAIDs can be estimated from only the TG signal. The approach with the TG method would be a new tool for evaluating photoreactivity of NSAIDs.