The dehalogenation of a selected number of I-chloro-4-acyloxy/oxy derivatives of thioxanthone have been studied by a spectropho~omcwic method, developed using the sodium salt of tetrabromophenol blue as the acid probe. The method has allowed the it, situ moAitoring of the photoacid generation by absorption spectroscopy. This has consequently lead to the evaluation of absolute quantum yields of acid gener'~ion through steady state photc, lysis, and the investigation of the derivatives as potential photoa,_'id generators, able to ini.'.iale cationic polymerisation ofcyclohexene oxide.

We thank The British Council, Madrid, Spain for awarding a special visit grant to M. Shah ( 1995-1996, 362/479) in support of this work.

Peer reviewed