Analysis of the time-resolved FTIR spectra produced by the photolysis of alkyl phenylglyoxylates

摘要

The photochemistry of alkyl phenylglyoxylates (APG) was further investigated using time-resolved infrared spectroscopy. The primary focus was on the analysis of weak transient bands around 1828 and 1730 cm~(-1) in the time-resolved FTIR spectra of glyoxylates. The observed transients were assigned to benzoyl and alkyl mandelate ester radicals, respectively. The formation of benzoyl radical was fast and attributed to the Ndrrish Type I process. In addition, the intensities of the strong FTIR bands around 1680 and 2100 cm~(-1) were used to analyze the yields of the triplet state and ketene, respectively. These new and previous data on APG photochemistry are discussed in relation to the acrylate polymerization photoinitiation by alkyl phenylglyoxylates.