Half-sandwich Ru(II), Ir(III) and Rh(III) complexes with bridging or chelating N-heterocyclic bis-carbene ligand: Synthesis and characterization

N-heterocyclic bis-carbene ligand (bis-NHC) which was derived from 1,1`-diisopropyl-3,3`-ethylenediimidazolium dibromide (L center dot 2HBr) via silver carbene transfer method, reacted with [(eta(6)-p-cymene) RuCl2](2) and [Cp*MCl2](2) (Cp* = eta(5)-C5Me5, M = Ir, Rh) respectively, afforded complexes [(eta(6)-p-cymene) RuCl2](2)(L) (1), [Cp*IrCl2](2)(L) (2) and [Cp*RhCl(L)][Cp*RhCl3] (3). When [Cp*IrCl2](2) was treated with 2 equiv AgOTf at first, and then reacted with bis-NHC ligand, [Cp*IrCl(L)]OTf (4) was obtained. The molecular structures of complexes 1-4 were determined by X-ray single crystal analysis, showing that 1 and 2 adopted bridging coordination mode, 3 and 4 adopted chelating coordination mode. All of these complexes were characterized by H-1, C-13 NMR spectroscopy and element analysis. (c) 2010 Elsevier B.V. All rights reserved.