Magnetic Isotope Effects in the Photolysis of Dibenzyl Ketone on Porous Silica. 13C and 17O Enrichments

Article abstract of DOI:10.1021/j100255a004

The photolysis of dibenzyl ketone (DBK) on porous silica has been investigated.Both 13C and 17O isotopic enrichment in the ketone remaining after partial photolysis is demonstrated.The efficiency of 13C enrichment was found to be relatively intensive to the average pore diameter of the silica host, to the percent coverage by DBK, and to the application of an external magnetic field.A significant dependence of 13C enrichment with temperature, with a maximum in the enrichment-temperature profile, was observed.The results are interpreted in terms of the competition between pathways available to the triplet C6H5CH2C^.O C^.H2C6H5 radical pair produced by photolysis of DBK.