Surface photochemistry: 13C enrichment by photolysis on silica gel

Abstract

The enrichment of the 13C isotope by partial photolysis of dibenzyl ketone on silica gel has been demonstrated. The 13C enrichment is substantial and is parallel to the increase in the probability of geminate radical recombination on a silica surface as compared with that in solution. A substantial 13C enrichment was also observed for the rearranged starting material, 1-phenyl-4′-methylacetophenone. The single-stage isotope separation factors are different for the two ketones although both are isomers derived from the same benzyl–phenylacetyl radical pairs.