PHOTOCHEMISTRY OF 9-ANTHRACENYLMETHYL-9'-FLUORENYL KETONE

The photolysis of the unsymmetric aromatic ketone 9-anthracenylmethyl- 9'-fluorenyl ketone (AFK) was studied using steady state and laser fla sh photolysis. Product studies from steady state illumination suggest that the compound photolyses from the singlet state by an inefficient Norrish type I process (psi almost-equal-to 0.01) to give anthrylmethy l, fluorenyl formyl and fluorenyl radicals which abstract protons from the solvent or recombine to give the expected products. The main prod uct observed on flash photolysis is a transient with an absorption max imum at 423 nm and a lifetime of approximately 24 mus. On the basis of quenching studies, this species is believed to be triplet AFK formed by rapid intersystem crossing of the singlet.