Photochemical dissociation of p-nitrobenzyl 9,10-dimethoxyanthracene-2-sulphonate via intramolecular electron transfer

Abstract

While o-nitrobenzyl aromatic sulphonates are known to photodissociate via an intramolecular rearrangement, photodissociation of p-nitrobenzyl aromatic sulphonates has not been reported. In this study, we report that p-nitrobenzyl 9,10-dimethoxyanthracene-2-sulphonate is photochemically dissociated to give 9,10-dimethoxyanthracene-2-sulphonic acid, 9,10-dimethoxy-2-(p-nitrobenzyl)-anthracene, and p,p′-dinitrobibenzyl. The dissociation is considered to proceed via an intramolecular electron transfer from the 9,10-dimethoxyanthracene moiety to the p-nitrobenzyl moiety. The quantum yield of the photodissociation in acetonitrile is 0.11 and the spectral response extends to 450 nm. The quantum yield is much higher than those of o-nitrobenzyl esters.