Bimetallic Ruthenium Complexes: Synthesis, Characterization, and the Effect of Appending Long Carbon Chains to Their Bridges

A series of binuclear ruthenium complexes [RuCl(CO)(PMe3)3]2(μ-CHCH−Ar−CHCH) (Ar = C6H2(OR)2-2,5; R = CH3 (4a), nC4H9 (4b), nC6H13 (4c), nC8H17 (4d), nC10H21 (4e), nC12H25 (4f), nC14H29 (4g)), [RuCl(CO)(PMe3)3]2(μ-CHCH−Ar−−Ar−CHCH) (Ar = C6H2(R)2-2,5; R = OCH3 (10a), OnC8H17 (10b), H (10c)), and [RuCl(CO)(PMe3)3]2(μ-CHCH−Ar−−Ar−−Ar−CHCH) (Ar = C6H2(R)2-2,5; R = OCH3 (13a), OnC8H17 (13b), H (13c)) have been synthesized. These complexes have been characterized by elemental analysis, NMR, and UV/vis spectrophotometry. The structures of 4b and 4d have been determined by X-ray crystallography. Electrochemical studies have shown that long carbon chains attached to the bridges of the complexes facilitate the stability of mixed-valence bimetallic ruthenium complexes.