The matrix isolation technique, combined with infrared spectroscopy and theoretical calculations, has been used to characterize the products of the photochemical reactions of chlorobenzene, α,α,α-trifluorotoluene, benzonitrile, and nitrobenzene with CrCl 2 O 2 . While initial twin jet deposition of the reagents led to no visible changes in the recorded spectra, product bands were noted following irradiation with light of λ>300nm. The irradiation was shown to lead to oxygen atom transfer, forming complexes between the corresponding cyclic ketone derivatives and CrCl 2 O. With benzonitrile, cyanophenol complexed to CrCl 2 O was also observed. This latter result arises from C–H bond activation and oxygen atom insertion into a C–H bond. The identification of the complexes were further supported by density functional calculations at the B3LYP/6-311G++(d,2p) level. Product distributions were rationalized by an analysis of the electron density distribution.