Chemiluminescence from arylcarbene oxidation: phenylchlorocarbene and (2-chlorophenyl)carbene

Article abstract of DOI:10.1016/0584-8539(87)80146-0

Chemiluminescence is observed in the thermal reaction of phenylchlorocarbene or (2-chloro-phenyl)carbene and O2, matrix-isolated in Ar.The chemiluminescence spectra closely match the phosphorescence of the corresponding carbonyl compounds.The reactivity of both carbenes towards O2 is very different.Singlet carbene phenylchlorocarbene reacts thermally only slowly with O2 up to 60 K.The oxidation products phenylchloroformate, benzoyl chloride and O(3P) are mainly formed photochemically on irradiation of the diazirine precursor.Triplet carbene (2-chlorophenyl)carbene reacts readily with O2 at cryogenic temperatures to give mostly 2-chlorobenzaldehyde-O-oxide.The carbonyl-O-oxide is photochemically easily cleaved to give 2-chlorobenzaldehyde and O(3P).The reaction step leading to carbonyl compounds in their excited states is in both carbene oxidations the recombination of the free carbene and O(3P).