Photoproduct formation and decay kinetics in the photochemical reduction of 2,2’-bipyrimidine (22BPMY) by aliphatic amines in H2O and D2O are determined by nanosecond, time-resolved resonance Raman spectroscopy. This analysis shows that the reaction scheme in aqueous solution differs from that observed in acetonitrile solution. The difference is accounted for by the existence of hydrogen bonding with the solvent in the excited state, which inhibits the formation of contact ion pair upon electron transfer.