The photo-excitation of anthracene (1) in the presence of benzoyl chloride and its p-or m- substituted compounds (2) gave the corresponding 2-and 9-aroylanthracenes. No isomeric 1-aroylanthracenes (3) were detected. The aroyl chlorides (2) were found to quench the fluorescence of 1. The quenching constants obtained increased with increasing electron- withdrawing ability of the substituents and are in agreement with those independently ...
