Synthesis and Redox Behavior of Ruthenium(II) 2,3,4,5-Tetramethylruthenocenylacetylide and Related Complexes. Formation of μ-η6:η1-[(Cyclopentadienylidene)ethylidene]diruthenium Complexes Containing a Strong Metal−Metal Interaction

Citations Over TimeTop 10% of 1999 papers

Abstract

1-Ethynyl-2,3,4,5-tetramethylruthenocene was prepared by the reaction of 1-formyl-2,3,4,5-tetramethylruthenocene with trimethylsilyldiazomethyllithium and also by the reaction of 1-(2‘,2‘-dichlorovinyl)-2,3,4,5-tetramethylruthenocene, which was obtained from the reaction of 1-formyl-2,3,4,5-tetramethylruthenocene with lithium dichloromethyldiethylphosphonate and tert-butyllithium in good yield. 1-Ethynyl-2,3,4,5-tetramethylruthenocene reacted with RuClP2L (P2 = 2 PPh3 or dppe; L = η-C5H5, η-C5Me5, or η5-C9H7) in the presence of NH4PF6 or AgBF4, followed by the column chromatography on deactivated Al2O3, to give Ru(C⋮CRc‘)P2L in moderate or good yield. Ru(C⋮CRc)P2(η5-C9H7) and Ru(C⋮CRc*)P2(η5-C9H7) were similarly prepared (Rc, Rc‘, and Rc* are ruthenocenyl, 2,3,4,5-tetramethylruthenocenyl, and 1‘,2‘,3‘,4‘,5‘-pentamethylruthenocenyl, respectively). The structures of Ru(C⋮CRc‘)(dppe)(PPh3)2(η-C5H5), Ru(C⋮CRc)(dppe)(η5-C9H7), and Ru(C⋮CRc‘)(dppe)(η5-C9H7) were determined by X-ray analysis. Cyclic voltammetry of the acetylide complexes showed two well-separated quasi-reversible waves. Chemical oxidation of ruthenium(II) 2,3,4,5-tetramethylruthenocenylacetylide complexes gave products whose stability was dependent on the ligand on the Ru(II) moiety. The 13C NMR spectrum of the oxidized species isolated as stable crystals confirmed the structural rearrangement of the bridging acetylide ligand to a μ-η6:η1-[(cyclopentadienylidene)ethylidene] ligand. The structure of [(η-C5H5)Ru(μ-η6:η1-C5Me4CC)Ru(dppe)(η5-C5Me5)](BF4)2 was determined by X-ray analysis.

Related Papers

• → Synthesis and characterisation of mono-acetylide and unsymmetrical bis-acetylide complexes of ruthenium and osmium: X-ray structure determinations on [(dppe)2Ru(Cl)(CC–C6H4-p-NO2)], [(dppe)2Ru(Cl)(CC–C6H3-o-CH3-p-NO2)] and [(dppm)2Os(CC–C6H4-p-CH3)(CC–C6H4-p-NO2)](1999)59 cited
• → Controlled Synthesis of Dinuclear Acetylide-Bridged Ruthenium Complexes(2010)28 cited
• → Ligand control of metal oxidation states. Synthesis, characterization and cyclic voltammetric studies of a group of ruthenium phenolates(1996)18 cited
• → Preparation and characterization of bisviologen-linked ruthenium (II) complexes(1998)6 cited
• → Alkynyl-ruthenium complexes for nonlinear optical applications(2008)