Oxygenation rate control by temperature with a thermoresponsive polymeric photosensitizer

ORGN 402

Hisao Koizumi, koizumi@cheng.es.osaka-u.ac.jp, Yasuhiro Shiraishi, shiraish@cheng.es.osaka-u.ac.jp, and Takayuki Hirai. Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, 560-8531, Japan
Design of photoreaction systems capable of promoting organic transformations in an economically and environmentally friendly way is one of the biggest challenges in chemistry. Here we report that a thermoresponsive polymeric photosensitizer, consisting of acrylamide and benzophenone units, acts as the first sensitizer enabling reversible photooxygenation rate control by temperature. We report here that this unprecedented photosensitizing activity is triggered by a heat-induced phase transition of the polymer, cleverly controlling the stability and diffusion of singlet oxygen and the location of substrate.