Département de chimie moléculaire

A novel approach for the synthesis of heteroleptic tris(diimine) ruthenium complexes is reported. This strategy is based on the electrochem. or chem. redn. of Ru(III) precursor complexes in MeCN such as [Ru(bpy)(X)Cl3] (bpy = 2,2'-bipyridine; X = MeCN (1) or MeOH (2)). This method allows the prepn. with high yield of the highly valuable [Ru(bpy)(MeCN)2Cl2] synthon (3). The full characterization (mass spectra, 1H NMR, absorption spectra, and electrochem.) of [Ru(bpy)(MeCN)2Cl2] (3) as a pure compd. is reported for the 1st time. Indeed the later was previously only obtained in mixts. with the corresponding tris(acetonitrile) deriv.: [Ru(bpy)(MeCN)3Cl]Cl. 1H NMR anal. of 3 indicates that its structure corresponds to the cis(Cl)-cis(MeCN) isomer form. [Ru(bpy)(MeCN)2Cl2] 3 was further used to synthesize [Ru(bpy)(Me2bpy)Cl2] (5) (Me2bpy = 4,4'-dimethyl-2,2'-bipyridine) for which x-ray anal. indicates that the two chloride ligands are also in cis position. [on SciFinder(R)]