Synthesis and some properties of binuclear ruthenocene derivatives bridged by both ethene and thiophene derivatives

Abstract

Binuclear ruthenocenes bridged by ethenes and thiophene derivatives, Rc–CH CH–Z–Rc and Rc ∗–CH CH–Z–CH CH–Rc ∗ (Z = thiophene, thieno[3,2- b]thiophene, and 2,2′-bithiophene; Rc = ruthenocenyl, R ∗ = 1′,2′,3′,4′,5′-pentamethylruthenocenyl) were prepared. These complexes showed a one-step two-electron redox wave in the cyclic voltammograms, in contrast to the benzenoid-bridged dinuclear ruthenocenes. The chemical oxidation of the Rc–CH CH–Z–Rc complexes gave no stable oxidized species. The two-electron oxidized species of the Rc ∗–CH CH–Z–CH CH–Rc ∗ complexes were comparably stable and contained a fulvene-complex type structure.