Molecular photochemical thermometers: investigation of microwave superheating effects by temperature dependent photochemical processes

摘要

The first study of temperature dependent photochemical reactions in the microwave field is reported. Two different photochemical processes: temperature dependent solvent effects inthe Norrish type II reaction and the photo-Fries reaction, were investigated under various thermal conditions including microwave heating. The former process exhibited a linear and reliable temperature dependence which served for the estimation of the microwave superheating effects in four different solvents. Their magnitudes were in a perfect agreement with the measured temperature enhancements. Thus, this photochemical system is proposed as a reliable molecular photochemical thermometer. The latter photochemical reaction studied showed a non-linear temperature dependence. All chemical changes inthe microwave field were rationalized as a consequence of thermal effects.