Application of laser photolysis to the study of reactive intermediates

Excimer laser flash photolysis in the study of diphenyl carbene (DPC) reveals the presence of at least three transient species produced by excitation of a precursor at 249 nm in isooctane solution at room temperature depending on the concentration of O2present. In an aerated solution, a fast first-order decay assigned to³DPC leads to the formation of an unassigned species which also decays by first order kinetics to produce the observed product Ph2CO. In degassed solution, the fast first-order decay of a species to produce³DPC which decays by second-order kinetics to produce the dimeric products observed.