Synthesis and Structural Characterization of a Dithiosilacarboxylate Dimer

The synthesis of a terphenyl-substituted lithium dithiosilacarboxylate dimer via the reaction of the corresponding aryltrifluorosilane with lithium (trimethylsilyl)thiolate is presented. Its molecular structure was determined by single-crystal X-ray diffraction analysis, which revealed a cis-geometry for the Si₂S₂ core in the crystalline state. Treatment of this complex with an excess of methyl iodide afforded the corresponding methyl ester dimer. Spectroscopic analyses suggested that neither the lithium dithiosilacarboxylate dimer nor the methyl dithiosilacarboxylate dimer dissociate homolytically in solution, not even at high temperatures.