Synthesis and electrochemical properties of bimetallic η5-indenyl ruthenium complexes

Abstract

Treatment of RuCl(dppm)(η5-C9H7) with alkynes HC≡C(C6H4)nC≡CH (n = 1, 2) in the presence of TlPF6 and t-BuONa affords the bimetallic ruthenium acetylide complexes [(η5-C9H7)(dppm)Ru]2(µ-C≡C(C6H4)nC≡C). Reactions of the hydride complex RuH(dppm)(η5-C9H7) with HC≡C(C6H4)nC≡CH (n = 1, 2) in refluxing toluene give the bimetallic ruthenium alkenyl complexes [(η5-C9H7)(dppm)Ru]2(µ-CH=CH(C6H4)nCH=CH). The electrochemical properties of the new complexes have been investigated by cyclic voltammetry, which reveals that the organic spacer –CH=CHC6H4CH=CH– is more effective than –C≡CC6H4C≡C– in mediating electronic communication between the two ruthenium moieties.Key words: ruthenium, bimetallic, acetylide, insertion, electrochemistry.