Synthesis of novel spirocyclic penta- and hexacoordinated germanium(IV) complexes

Article abstract of DOI:10.1021/ic50226a019

The reactions of GeCl₄ with catechol, 3,5-di-tert-butylcatechol, and toluene-3,4-dithiol in the presence of triethylamine have been investigated. The spirocyclic derivatives isolated from these reactions are Ge(C₆H₄O₂)₂·2H₂O (5), [(Cl)Ge(C₁₄H₂₀O₂)₂][Et ₃NH] (14), and Ge(C₇H₆S₂)₂ (4). Physical properties and solubility behavior of 4 and 5 suggest a polymeric structure. The complex 14 contains pentacoordinate germanium(IV). This complex reacts with water to form the corresponding hydroxy derivative, [(OH)Ge(C₁₄H₂₀O₂)₂][Et ₃NH] (15). Reaction of GeCl₄ with catechol in triethylamine only and the reaction of 5 with triethylamine give rise to the exclusive formation of a spirocyclic hexacoordinated Ge(IV) complex, [Ge(C₆H₄O₂)₃][Et₃NH] ₂ (10). A metathesis reaction of 10 with Et₄N⁺Cl^- leads to the formation of [Ge(C₆H₄O₂)₃][Et₄N] ₂ (11). A similar reaction of 14 with Et₄N⁺Cl^- in the presence of water gives [(OH)Ge(C₁₄H₂₀O₂)₂][Et₄N] (16). Several novel spirocyclic pentacoordinated Ge(IV) complexes have been prepared by the reaction of 4 and 5 with halide ions and characterized by ¹H NMR spectroscopy. The chemical properties, in particular the hydrolytic behavior of these complexes, are discussed.