Sulfonium salts, pyramidal structure

Trimercaptosulfonium salts were prepared by reacting CI>S 1 salts with excess H2S248 [Eq. (4.67)]. According to calculation, the pyramidal structure of C3v symmetry is the energy minimum structure with the S—H bonds pointing toward the top of the pyramid. The corresponding dimercapto(methyl)sulfonium salts were also synthesized in an analogous way.249 The products were transformed into chlorothio derivatives [Eq. (4.68)]. 

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