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

摘要

N-heterocyclic bis-carbene ligand (bis-NHC) which was derived from 1,1′-diisopropyl-3,3′-ethylenediimidazolium dibromide (L·2HBr) via silver carbene transfer method, reacted with [(η~6-p-cymene)RuCl_2]_2 and [Cp ~1MCl_2]_2 (Cp~1 = η~5- C_5Me_5, M = Ir, Rh) respectively, afforded complexes [(η~6-p-cymene)RuCl_2]_2(L) (1), [Cp ~1IrCl_2]_2(L) (2) and [Cp~1RhCl(L)] [Cp~1RhCl_3] (3). When [Cp~1IrCl_2] _2 was treated with 2 equiv AgOTf at first, and then reacted with bis-NHC ligand, [Cp~1IrCl(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 ~1H, ~(13)C NMR spectroscopy and element analysis.