An EPR investigation of persistent radicals from the photolysis of p,p ' dialkyl-substituted phenyl benzyl ketones adsorbed on MFI zeolites

The photolysis of isomeric pairs of p,p'-dialkyl-substituted phenyl benzyl ketones adsorbed on MFI zeolites has been investigated by EPR spectroscopy, Photolysis produces persistent "benzoyl type" and "benzyl type" radicals, The dominant persistent radical produced by photolysis of any particular is omeric pair depends on the length and position of the p-alkyl chain, The re sults are attributed to supramolecular stereoisomers resulting from prefere ntial adsorption of the longer alkyl chain into the pores of the zeolite.