Gendy Chris, Mansikkamäki Akseli, Valjus Juuso, Heidebrecht Joshua, Hui Paul Chuk-Yan, Bernard Guy M, Tuononen Heikki M, Wasylishen Roderick E, Michaelis Vladimir K, Roesler Roland
Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
Department of Chemistry, Nanoscience Centre, University of Jyväskylä, 40014, University of Jyväskylä, Finland.
Angew Chem Int Ed Engl. 2019 Jan 2;58(1):154-158. doi: 10.1002/anie.201809889. Epub 2018 Nov 27.
Flexible, chelating bis(NHC) ligand 2, able to accommodate both cis- and trans-coordination modes, was used to synthesize (2)Ni(η -cod), 3. In reaction with GeCl , it produced (2)NiGeCl , 4, featuring a T-shaped Ni and a pyramidal Ge center. Complex 4 could also be prepared from [(2)GeCl]Cl, 5, and Ni(cod) , in a reaction that formally involved Ni-Ge transmetalation, followed by coordination of the extruded GeCl moiety to Ni. A computational analysis showed that 4 possesses considerable multiconfigurational character and the Ni→Ge bond is formed through σ-donation from the Ni 4s, 4p, and 3d orbitals to Ge. (NHC) Ni(cod) complexes 9 and 10, as well as (NHC) GeCl derivative 11, incorporating ligands that cannot accommodate a wide bite angle, failed to produce isolable Ni-Ge complexes. The isolation of (2)Ni(η -Py), 12, provides further evidence for the reluctance of the (2)Ni fragment to act as a σ-Lewis acid.
柔性螯合双（NHC）配体2能够适应顺式和反式配位模式，用于合成(2)Ni(η -环辛二烯)，即3。在与GeCl反应时，它生成了(2)NiGeCl，即4，其具有T形的镍和金字塔形的锗中心。配合物4也可以由[(2)GeCl]Cl，即5，和Ni(环辛二烯)，通过一个正式涉及镍-锗金属转移的反应制备，随后挤出的GeCl部分与镍配位。计算分析表明4具有相当大的多构型特征，并且镍→锗键是通过从镍的4s、4p和3d轨道向锗的σ供体作用形成的。（NHC）Ni(环辛二烯)配合物9和10，以及包含不能适应宽咬角配体的（NHC）GeCl衍生物11，未能生成可分离的镍-锗配合物。(2)Ni(η -吡啶)，即12的分离，为(2)Ni片段不愿作为σ-路易斯酸提供了进一步的证据。
