804500-06-9Relevant academic research and scientific papers
Synthesis and structure of new (Polyphosphane)ruthenium complexes with the hemilabile ligand 2-(Diphenylphosphanyl)-1-methyl-1H-imidazole - An unexpected rearrangement of [RnCl2(PN)(PPh3)2]
Espino, Gustavo,Jalon, Felix A.,Maestro, Miguel,Manzano, Blanca R.,Perez-Manrique, Mercedes,Bacigalupe, Ana C.
, p. 2542 - 2552 (2007/10/03)
Several RuII complexes containing the potentially bidentate ligand 2-(diphenylphosphanyl)-1-methyl-1H-imidazole [PPh2MeIm (PN)] have been synthesised and characterised. Reaction of the ligand with [RuCl 2(PPh3)3] in different molar ratios led to the formation of the complexes trans,mer[RuCl2(PPh3) 2(κ2-P,N-PPh2MeIm)] (1), fac-[RuCl(PPh3)(κ2-P,N-PPh2MeIm) 2]Cl (2a), mer-[RuCl(PPh3)(κ2-PN-PPh 2MeIm)2]Cl (2b), fac-[RuCl(κ1-P-PPh 2MeIm)(κ2-P,N-PPh2MeIm)2]Cl (3a), and mer-[RuCl(κ1-P-PPh2MeIm)(κ2-PN- PPh2MeIm)2]Cl (3b). Complex 1 evolves in solution to 2a, 2b and the dinuclear species [(PPh3)(κ1-P-PPh 2MeIm)ClRu(μ-Cl)2Ru(PPh3) (κ1-P-PPh2MeIm)Cl] (4a), [(PPh3) ClRu(μ-Cl)2(μ2-P,N-PPh2MeIm)2Ru(PPh 3)Cl] (4b), and [(PPh3)(κ2-P,N-PPh 2MeIm) ClRu(μ-Cl)2Ru(PPh3) (κ2-P,N-PPh2MeIm)Cl] (4c). It is proposed that the formation of the dinuclear derivatives involves an Ru-N bond-breaking step that demonstrates the hemilabile behaviour of the ligand. When 2 equiv. of the PN ligand were added to [RuCl2(cod)(bpzm)] [cod = 1,5-cyclooctadiene, bpzm = bis(pyrazol-1-yl)methane], the complex cis-P-[RuCl2(κ 1-PPh2MeIm)(κ2-PPh2MeIm)] (5) was formed as the only product. The derivatives [Ru(κ2-PPh 2MeIm)3]X2 [(X = PF6 (6), BF 4 (7)] were obtained upon treatment of [RuCl2(arene)] 2 (arene = p-cymene, benzene) with 2 equiv. of the corresponding silver salts and the PN ligand. Both the fac (6a, 7a) and mer (6b, 7b) forms were obtained. Two new hydride complexes were also synthesised: mer-[RuHClL 2(κ2-PPh2MeIm)] [L = PPh3 (8) or κ1-PN (9)] by reaction of the PN ligand with [RuHCl(PPh 3)3] or [RuHCl(cod)(bpzm)], respectively. The molecular structure of 4b and fac-7a was solved by an X-ray diffraction study. Complex 4b has a dinuclear structure with two chloride bridges and two head-to-tail PN bridges. The derivative fac-7a is mononuclear, Both enantiomers - A and A - were observed in the same unit cell. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
