Vacuum-Ultraviolet Photochemistry. IV. Primary Processes in the Photolysis of Water at 1470 Å

Abstract

Water has been photolyzed at 1470 Å in the absence and presence of ethylene which acts as a scavenger for hydrogen atoms. Mixtures of D2O and C2H4 were used to distinguish between hydrogen from the photolysis of water and from the photolysis of ethylene. In the presence of 5% and 20% C2H4, the rate of D2 production from the photolysis of D2O is 6% of that in the absence of C2H4. It is concluded that in the photolysis of D2O at 1470 Å, there are two primary processes occurring: D2O+hv1470Å→D+OD,D2O+hv1470Å→D2+O.Direct production of molecular hydrogen and atomic oxygen accounts for 6% of the primary processes.