KINETIC-ANALYSIS BY TRANSIENT RAMAN-SPECTROSCOPY OF THE PHOTOREDUCTION OF 2,2'-BIPYRIMIDINE BY AMINES IN WATER

Photoproduct formation and decay kinetics in the photochemical reducti on of 2,2'-bipyrimidine (22BPMY) by aliphatic amines in H2O and D2O ar e determined by nanosecond, time-resolved resonance Raman spectroscopy . This analysis shows that the reaction scheme in aqueous solution dif fers from that observed in acetonitrile solution. The difference is ac counted for by the existence of hydrogen bonding with the solvent in t he excited state, which inhibits the formation of contact ion pair upo n electron transfer.