Synthesis and characterization of a dinuclear Ni complex containing a bridging CNC pincer ligand

The reaction of the bis(carbene) pincer ligand (CNC)-C-Me with nickel acetate and Bu4NBr produced [((CNC)-C-Me)(3)Ni-2](4+)[Br](4) (2), a complex that contains the (CNC)-C-Me ligand in both traditional tridentate chelating modes as well as in a unique, bridging mode between two Ni2+ ions. While 2 could not be crystallized or isolated in a pure form, the anion exchange of bromide with triflate yielded [((CNC)-C-Me)(3)Ni-2](4+)[OTf](4) (4), which could be recrystallized from methanol and isolated pure. Single-crystal X-ray analysis of 4 confirmed the unusual dual-coordination modes of the (CNC)-C-Me ligand towards Ni2+ in these species, and represents the initial example of a Group 10 complex of a bridging CNC ligand. (C) 2010 Elsevier B.V. All rights reserved.