Syntheses, spectroscopic properties and crystal structures of two organoruthenium (II) complexes of bipyridines: [{Cp*Ru(2,2′-bipy)}2(μ-Cl)][PF6] and [{(η6-p-cymene)Ru}2(μ-OH)2(4,4′-bipy)]2[BF4]4

Interaction of [Cp*RuCl(μ-Cl)]2 with 2,2′-bipyridine (2,2′-bipy) in the presence of Na[PF6] gave a chloride bridging dinuclear complex [{Cp*Ru(2,2′-bipy)}2(μ-Cl)][PF6] (1). In the crystal structure, the cation [{Cp*Ru(2,2′-bipy)}2(μ-Cl)]+ contains a bent Ru–Cl–Ru linkage with an angle of 141.87(12)°. The tris(μ-hydroxo)diruthenium complex [{(η6-p-cymene)Ru}2(μ-OH)3][BF4] in acetone solution was treated by 4,4′-bipyridine (4,4′-bipy) to give a hydroxo-bridged tetranuclear complex [{(η6-p-cymene)Ru}2(μ-OH)2(μ-4,4′-bipy)]2[BF4]4 (2). Complex 2 consists of four (η6-p-cymene)Ru moieties connected by two 4,4′-bipy and four hydroxo-bridging groups, forming a novel metallomacrocycle with alternating hydroxyl and 4,4′-bipy bridges between the ruthenium atoms. Spectroscopic properties along with electrochemistry of two organoruthenium (II) complexes 1 and 2 are reported.

Graphical abstractTwo new cationic polynuclear organoruthenium (II) complexes are reported. Dinuclear Cp*Ru complex [{Cp*Ru(2,2′-bipy)}2(μ-Cl)][PF6] (1) contains a labile chloride ligand in the bent Ru–Cl–Ru linkage and tetranuclear (η6-p-cymene)Ru complex [{(η6-p-cymene)Ru}2(μ-OH)2(4,4′-bipy)]2[BF4]4 (2) shows a novel metallomacrocyclic structure with hydroxo bridges.Figure optionsDownload full-size imageDownload as PowerPoint slide