Bulky arene-bridged bis(amide) and bis(amidinate) complexes of germanium(ii) and tin(ii)

Abstract

Several new, very bulky arene-bridged bis(amine) (viz. 1,3- and 1,4-{N(H)(SiPrⁱ₃)}₂(μ-C₆H₄), L¹H₂ and L²H₂, respectively) and bis(amidine) pro-ligands (viz. 4,6-{[Dip(H)N](DipN)C}₂(μ-DBF), DBF = dibenzofurandiyl, L³H₂; and 1,3-{Ar^†N(H)C(Bu^t)N}₂(μ-C₆H₄), Ar^† = C₆H₂{C(H)Ph₂}₂Prⁱ-2,6,4, L⁴H₂) have been developed. All can be doubly deprotonated with LiBuⁿ. The resultant dilithium salts react with either GeCl₂·(dioxane) or SnBr₂ to yield a series of amidotetrelylenecyclophanes (:E(μ-L¹)₂E: and :E(μ-L²)₂E:, E = Ge or Sn) and bis(halotetrelylene) complexes (:E(X)(μ-L³)(X)E:, E = Ge or Sn, X = Cl or Br; and :Ge(Cl)(μ-L⁴)(Cl)Ge:). Reduction of :Ge(Cl)(μ-L⁴)(Cl)Ge: with KC₈ afforded the crystallographically characterised bis(amido/amidinatogermylene) compound, :Ge(μ-L⁴)₂Ge:, which is believed to have formed via a disproportionation process.