INTRAMOLECULAR END-TO-END REACTIONS OF PHOTOACTIVE TERMINAL GROUPS LINKED BY POLYMETHYLENE CHAINS.

Article abstract of DOI:10.1021/ja00209a032

Intramolecular end-to-end reactions of a pair of photoactive terminal groups, dibenz left bracket b,f right bracket azepine (DBA) chromophores, linked by a series of polymethylene chains (DBA-CO(CH//2)//nCO-DBA, n equals 2-30) were studied by two different approaches. One approach is to measure the intramolecular deactivation rate constants of the excited triplet state of terminal DBA groups by the nanosecond laser photolysis and the other is to measure the intramolecular photocyclization rates of these bichromophoric compounds by the quantitative product analysis with GPC. The excited triplet state of the DBA group is the intermediate of the reaction.