Ammonia Activation by a Nickel NCN‐Pincer Complex featuring a Non‐Innocent N‐Heterocyclic Carbene: Ammine and Amido Complexes in Equilibrium1. Issue 21 (13th April 2015)

• Record Type: Journal Article
• Authors: Brown, Rudy M.; Borau Garcia, Javier; Valjus, Juuso; Roberts, Christopher J.; Tuononen, Heikki M.; Parvez, Masood; Roesler, Roland
• Is Part Of: Angewandte Chemie international edition. Volume 54:Issue 21(2015)
• Page Start: 6274
• Page End: 6277
• Publication Date: 2015-04-13
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201500453
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A Ni⁰‐NCN pincer complex featuring a six‐membered N‐heterocyclic carbene (NHC) central platform and amidine pendant arms was synthesized by deprotonation of its Ni^II precursor. It retained chloride in the square‐planar coordination sphere of nickel and was expected to be highly susceptible to oxidative addition reactions. The Ni⁰ complex rapidly activated ammonia at room temperature, in a ligand‐assisted process where the carbene carbon atom played the unprecedented role of proton acceptor. For the first time, the coordinated (ammine) and activated (amido) species were observed together in solution, in a solvent‐dependent equilibrium. A structural analysis of the Ni complexes provided insight into the highly unusual, non‐innocent behavior of the NHC ligand.</p> </abstract>