Mono and dinuclear arene ruthenium complexes containing 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline as chelating ligand: Synthesis and molecular structure

Abstract

The mononuclear cations of the general formula [(η 6-arene)RuCl(dpqMe 2)] + (dpqMe 2 = 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline; arene = C 6H 6, 1; C 6H 5Me, 2; p-Pr i C 6H 4Me, 3; C 6Me 6, 4) as well as the dinuclear dications [(η 6-arene) 2Ru 2Cl 2(μ-dpqMe 2)] 2+ (arene = C 6H 6, 5; C 6H 5Me, 6; p-Pr i C 6H 4Me, 7; C 6Me 6, 8) have been synthesised from 6,7-dimethyl-2,3-di(pyridine-2-yl)quinoxaline (dpqMe 2) and the corresponding chloro complexes [(η 6-C 6H 6)Ru(μ-Cl)Cl] 2, [(η 6-C 6H 5Me)Ru(μ-Cl)Cl] 2, [(η 6- p-Pr i C 6H 4Me)Ru(μ-Cl)Cl] 2 and [(η 6-C 6Me 6)Ru(μ-Cl)Cl] 2, respectively. The X-ray crystal structure analyses of [ 1][PF 6], [ 3][PF 6] and [ 6][PF 6] 2 reveal a typical piano-stool geometry around the metal centre; in the dinuclear complexes the two chloro ligands, with respect to each other, are found to be trans oriented.