Synthesis and Structure of [{PhC(NtBu)2}2Ge2(μ-S)2Cl2] and a Germanium Dithiocarboxylate Analogue

LGeCl (L = PhC(NtBu)2) was treated with elemental sulfur in THF to afford [{PhC(NtBu)2}2Ge2(μ-S)2Cl2] (2) in 44% yield instead of yielding a compound containing a GeS double bond. It was revealed by the X-ray single-crystal structure that there is no GeS unit in 2. Instead, 2 features a four-membered ring containing two germanium and two sulfur atoms. The four-membered Ge2S2 ring is planar and is formed by a weak [2 + 2] cycloaddition interaction. Within the ring skeleton the two germanium atoms are arranged opposite to each other. Furthermore, 2 was reduced with 2 equiv of potassium graphite in THF to yield a potassium salt of a germathiocarboxylate analogue of composition [{PhC(NtBu)2}Ge(S)SK(THF)]2 (3). Compounds 2 and 3 were characterized by single-crystal X-ray diffraction studies, NMR spectroscopy, EI-MS spectrometry, and elemental analysis.