The photochemistry of 9,10-anthracenedione in sulfuric acid solution. The dependence of product yields on reaction conditions

Abstract

Irradiation of a sulfuric acid solution of 9,10-anthracenedione with near-uv light generated 2-hydroxy-9,10-anthracenedione as the major product. In addition, the 1-hydroxy and polyhydroxy derivatives and the reduction products anthrone and bianthronyl were also formed. The yields of these minor produets were markedly influenced by the concentrations of water and oxygen in the sulfuric acid. At low light intensities, oxygen quenched the efficient formation of the hydroxyanthracenediones and also oxidised the initial quinone reduction products. Photoreduction of the anthracenedione and photooxidation of anthrone occurred simultaneously in the solution. The reaction mechanism is more complex than previous studies indicated.