Pulse radiolytic generation and photolysis of diphenyldiazomethane radical anion (Ph2CN2−.)

Diphenyldiazomethane radical anion (Ph2Cn2−.) has been generated by pulse radiolytic reduction of diphenyldiazomethane (Ph2CN2) in acetonitrile. Subsequent pulse laser excitation within the electronic absorption band of Ph2CN2−. (λmax=370 nm) results in a strong irreversible bleach of the absorption signal and a simultaneous appearance of a secondary absorption band (λmax=330 nm). The secondary transient is attributed to diphenylmethyl radical (Ph2ĊH) formed by protonation of diphenylcarbene radical anion (Ph2C−.) within the laser excitation pulse.