Generation and Transient Spectroscopy of Substituted Diaryl Carbonyl Oxides

Article abstract of DOI:10.1021/jo00268a023

Spectroscopic and kinetic parameters for a variety of substituted diaryl carbonyl oxides in solution at room temperature are reported.These species are generated by direct reaction of oxygen with the triplet carbene derived from the corresponding diazo compound or by reaction of the diazo compound with singlet oxygen.Typically, diaryl-substituted carbonyl oxides have absorption maxima in the 400-450-nm region and decay with second-order kinetics.For example, the parent benzophenone oxide (λ_max 410 nm) can be formed by reaction of the carbene with oxygen (k_O2 5.0E9 M^-1s^-1) or by reaction of singlet oxygen with the diazo precursor (k_D = 1.0E9 M^-1s^-1).It decays by-self-reaction with k = 1.33E7 M^-1s^-1 in acetonitrile and can be readily scavenged by aldehydes, e.g. for acetaldehyde k₃ = 3.1E6 M^-1s^-1.