| Sumario: | The low electron count Pt(II) complexes [Pt(NHC′)(NHC)][BAr] (where NHC is a N-heterocyclic carbene ligand and NHC′ its metalated form) react with tertiary hydrogermanes HGeRat room temperature to generate the 14-electron platinum(II) germyl derivatives [Pt(GeR)(NHC)][BAr]. Low-temperature NMR studies allowed us to detect and characterize spectroscopically some of the σ-GeH intermediates [Pt(η-HGeR)(NHC′)(NHC)][BAr] that evolve into the platinum-germyl species. One of these compounds has been characterized by X-ray diffraction studies, and the interaction of the H-Ge bond with the platinum center has been analyzed in detail by computational methods, which suggest that the main contribution is the donation of the H-Ge to a σ*(Pt-C) orbital, but backdonation from the platinum to the σ*(Ge-H) orbital is significant. Primary and secondary hydrogermanes also produce the corresponding platinum-germyl complexes, a result that contrasts with the reactivity observed with primary silanes, in which carbon-silicon bond-forming reactions have been reported. According to density functional theory calculations, the formation of Pt-Ge/C-H bonds is both kinetically and thermodynamically preferred over the competitive reaction pathway leading to Pt-H/C-Ge bonds.
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