Photochemical generation of acrylate radicals by sensitizing with acetone–propan-2-ol. A laser photolysis Fourier transform electron paramagnetic resonance study

Abstract

The sensitized generation of acrylate radicals was studied in acrylate–acetone–propan-2-ol solution by using laser photolysis with time-resolved Fourier transform electron paramagnetic resonance (EPR). In addition to the acetone ketyl radical, vinyl-type radicals of various acrylates were observed in the nanosecond and microsecond time scales. Classification as vinyl-type radical structures was underpinned by quantum-chemical calculations. The acrylate radicals were E/A spin-polarized by the CIDEP radical pair mechanism as described. A triplet exciplex is proposed as the precursor state of the acetone–acrylate radical pair. This interpretation is supported by quantum-chemical calculations.