Chelating ligands have had a tremendous impact in coordination chemistry and catalysis. Notwithstanding their success as strongly σ-donating and π-accepting ligands, to date no chelating bis[cyclic (alkyl)(amino)carbenes] have been reported. Herein, we describe a chelating, C₂-symmetric bis[cyclic (alkyl)(amino)carbene] ligand, which was isolated as a racemic mixture. The isolation and structural characterization of its isostructural, pseudotetrahedral complexes with iron, cobalt, nickel, and zinc dihalides featuring eight-membered metallacycles demonstrates the binding ability of the bis(carbene). Reduction of the nickel(II) dibromide with potassium graphite produces a dicoordinate nickel(0) complex that features one of the narrowest angles measured in any unsupported dicoordinate transition metal complexes.

螯合配体对配位化学和催化产生了巨大影响。尽管它们作为强σ-供体和π-接受配体取得了成功，但迄今为止尚未报道螯合双[环(烷基)(氨基)卡宾]。在此，我们描述了一种螯合的C ₂ -对称双[环(烷基)(氨基)卡宾]配体，其作为外消旋混合物被分离。其与铁、钴、镍和锌二卤化物（具有八元金属环）的同构假四面体配合物的分离和结构表征证明了双（卡宾）的结合能力。用钾石墨还原二溴化镍 (II) 会产生双配位镍 (0) 配合物，其特征是在任何无载体双配位过渡金属配合物中测得的最窄角度之一。