Electron-beam induced reactions of sulfonium salts in a crystalline state

Enomoto, Kazuyuki*; Maekawa, Yasunari; Moon, S.; Shimoyama, Junji*; Goto, Kazuyuki*; Narita, Tadashi*; Yoshida, Masaru

The Electron beams (EB)-induced reactions of triphenylsulfonium methanesulfonate (1) in the crystalline state gave benzene-substituted product, biphenylsulfonium methanesulfonate (2), which has not been observed by either photolysis. In this paper, the EB-induced reactions of triphenylsulfonium salt derivatives, which possesses aromatic/aliphatic counter anions, have been examined. The anionic moiety of sulfonium salts has practically little effect on the formation of biphenyl salt 2 as well as the other products. The consumption rates of the sulfonium salts containing aromatic counter anions are somewhat smaller in a crystalline state and about two times larger than those of the salts with aliphatic counter anions. The greater decomposition rates of the sulfonium salts with aromatic counter anions than those of aliphatic counter anions in an amorphous state are elucidated by lower ionization potential of the salts with aromatic counter anions such as tosyl and naphthyl groups than those with aliphatic counter anions.