Synthesis, structure and a nucleophilic coordination reaction of Germanetellurones

Abstract

β-Diketiminato cyclopentadienyl and ferrocenylethynyl germylenes LGeR (L = HC[C(Me)N-2,6-iPr₂C₆H₃]₂, R = Cp (1) and CCFc (2)) were prepared and utilized to synthesize the GeTe bond species. Reactions of 1, 2, and LGeCCPh (3) with an excess of Te powder proceeded in toluene under reflux successfully yielded germanetellurone L(R)GeTe (R = Cp (4), CCFc (5), and CCPh (6)). Further reaction of 4 with GeCl₂·dioxane at −78 °C resulted in L(Cp)GeTe(GeCl₂) (7), the first example of a germylene germanetellurone adduct. Both compounds 4 and 7 contain two isomers that are generated by the simultaneous 1,2-H- and 1,3-H-shifts over the Cp ring at the Ge atom. The reactions of L(Me)GeE with AuC₆F₅·SC₄H₈ at room temperature led to pentafluorophenyl gold(I) germanethione and germaneselone compounds L(Me)GeE(AuC₆F₅) (E = S (8) and Se (9)). The formation of compounds 7–9 exhibits a rare nucleophilic coordination reaction pathway by the GeE (E = S, Se, Te) bond towards the metal-containing Lewis acidic species. The structures of compounds 1, 2, and 4–9 are studied by the NMR and/or IR spectroscopy and X-ray crystallography.