Aryl-substituted and fused heterocyclic sulfonium salts prepared from the corresponding sulfoxides and derivatives of aromatic hydrocarbons in the presence of dehydrating agents are efficient initiators of cationic polymerization and find a number of other commercially important applications [1, 2]. In patents [3 7] as photo- initiators are recommended sulfonium salts based on derivatives of 9H-thioxanthen-9-one, thianthrene, di- benzothiophene, and other heterocyclic ...
