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Updated: Feb 25, 2026

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area
Published on: February 19, 2018
Tritopic NHC Precursors: Unusual Nickel Reactivity and Ethylene Insertion into a C(sp3 )-H Bond
Xiaoyu Ren1, Christophe Gourlaouen2, Marcel Wesolek1
1Laboratoire de Chimie de Coordination, Institut de Chimie (UMR 7177 CNRS), Université de Strasbourg, 4 rue Blaise Pascal, 67081, Strasbourg Cedex, France.
Abstract:
The imidazolium chloride [C3 H3 N(C3 H6 NMe2 )N{C(Me)(=NDipp)}]Cl (1; Dipp=2,6-diisopropyl phenyl), a potential precursor to a tritopic Nimine CNHC Namine pincer-type ligand, reacted with [Ni(cod)2 ] to give the NiI -NiI complex 2, which contains a rare cod-derived η3 -allyl-type bridging ligand. The implied intermediate formation of a nickel hydride through oxidative addition of the imidazolium C-H bond did not occur with the symmetrical imidazolium chloride [C3 H3 N2 {C(Me)(=NDipp)}2 ]Cl (3). Instead, a Ni-C(sp3 ) bond was formed, leading to the neutral Nimine CHNimine pincer-type complex Ni[C3 H3 N2 {C(Me)(=NDipp)}2 ]Cl (4). Theoretical studies showed that this highly unusual feature in nickel NHC chemistry is due to steric constraints induced by the N substituents, which prevent Ni-H bond formation. Remarkably, ethylene inserted into the C(sp3 )-H bond of 4 without nickel hydride formation, thus suggesting new pathways for the alkylation of non-activated C-H bonds.
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