Dinuclear organogermanium chalcogenide complexes as intermediates towards functionalized clusters

摘要

Reactions of (RGeCl3)-Ge-1 (R-1 = CMe2CH2COMe) with (Me3Si)(2)E (E = S, Se, Te) yield three new organogermanium chalcogenide complexes [((RGeCl)-Ge-1)(2)S-2] (1), [(R1GeCl)(2)Se-2] (2), and [((RGeCl)-Ge-1)(2)Te-2] (3) with functionalized ligands R-1 = CMe2CH2COMe. NMR titration experiments clearly demonstrate that these dimeric complexes are intermediates in the formation of the well-known sesquichalcogenide clusters [((RGe)-Ge-1)(4)E-6]. In striking contrast to related tin compounds that were recently reported, the mono-bridged complexes of the type "[((RGeCl2)-Ge-1)(2)E]" and defect-heterocubane-type clusters "[((RGe)-Ge-1) 3E4Cl]" do not form on the NMR time scale for E = S or Te, and only in traces for E = Se.