Reaction of Diphenylmethylene and Phenylmethylene with Oxygen. A Matrix Isolation Study

Article abstract of DOI:10.1021/jo00263a014

The thermal and photochemical reactions of phenylcarbene and diphenylcarbene in oxygen-doped matrices have been investigated.The primary thermal adducts of free carbenes and O2 are carbonyl O-oxides, which are characterized by IR and UV spectroscopy.Most characteristic are intense O-O stretching modes in the IR (ν=900 cm^1-) and ?-->?^* transitions in the UV (λ=400 nm) spectra.The carbonyl O-oxides are very photolabile toward long-wavelength irradiation (500-630 nm) and either rearrange to dioxiranes or split off oxygen atoms.The distribution of photoproductsis determined by substituents: benzophenone O-oxide mainly gives diphenyldioxirane while benzaldehyde O-oxide gives the aldehyde and oxygen atoms.The strong chemiluminescence observed during the thermal reaction is explained by the reaction of free carbenes and oxygen atoms forming a C=O bond in situ.This reaction is highly exothermic and produces carbonyl compounds in their triplet states.