Radiation-induced reactions of benzoyl chloride and acrylates in solution. A pulse radiolysis study

Abstract

Using electron pulse radiolysis with optical detection, the radiation-induced reactions of benzoyl chloride and acrylates were studied in tetrahydrofuran and acetonitrile solution at room temperature. In both solvents electron transfer leads to the formation of transient radical anions of acrylates (k≈2–3×1010 dm3 mol−1 s−1) and of benzoyl chloride (k≈3×1010 dm3 mol−1 s−1). The latter dissociates into chloride ion and the benzoyl radical (k=3×106 s−1), whereas the acrylate anion transforms by protonation into a ketyl-type radical. In mixed solutions a fast electron transfer from acrylate anions to benzoyl chloride is found (k≈1×1010 dm3 mol−1 s−1). The benzoyl chloride anion reacts with the monomer (k=2.8×109 dm3 mol−1 s−1) with simultaneous release of Cl−, forming species which may initiate polymerization. In the presence of oxygen the formation of benzoylperoxy radicals (k=1.6×109 dm3 mol−1 s−1), showing a strong absorption band in the near-UV (λmax=400 nm), is observed.