Photoinitiation of polymerization and hydrogen abstraction by metal carbonyls

Abstract

Os₃(CO)₁₂ and Re₂(CO)₁₀ when irradiated by light of λ= 365 nm initiate the polymerization of methyl methacrylate and acrylonitrile in the absence of organic halide; species arising from photoexcitation of the carbonyls are shown to abstract hydrogen from hydrocarbons to form the corresponding free radicals, and it is suggested that similar hydrogen abstraction from monomer is the origin of photoinitiation under the present conditions.