ON THE MECHANISM OF THE PHOTOCHEMICAL REACTION BETWEEN 1,4-NAPHTHALENEDICARBONITRILE AND METHYLBENZENES

Article abstract of DOI:10.1021/ja00324a026

On the basis of the correlation between fluorescence quenching and reaction quantum yield and of deuteration studies, it is shown that the photochemical reaction between 1,4-naphthalenedicarbonitrile (NDN) and methylbenzenes involves (i) water-mediated proton transfer within the charge-transfer exciplex, (ii) in-cage reaction of the two radicals to form 2-benzyl-1,2-dihydro-1,4-naphthalenedicarbonitrile (2) and 6,11-dicyano-5,11-methano-5,6,11,12-tetrahydrodibenzocyclooctene (3), the formation of the latter product requiring a further water-mediated hydrogen transfer, and (iii) escape of the benzylic radical, which is trapped by NDN, to give 4-benzyl-1-naphthalenecarbonitrile (1), a product formed also when benzylic radicals are generated from other sources.