Synthesis and electrochemical properties of bimetallic eta(5)-indenyl ruthenium

Treatment of RuCl(dppm)(eta(5)-C9H7) with alkynes HC C(C6H4)(n)C CH (n = 1, 2) in the presence of TlPF6 and t-BuONa affords the bimetallic ruthenium acetylide complexes [(eta(5)-C9H7)(dppm)Ru](2)(mu-C C(C6H4)(n)C C). Reactions of the hydride complex RuH(dppm)(eta(5)-C9H7) with HC C(C6H4)(n)C CH (n = 1, 2) in refluxing toluene give the bimetallic ruthenium alkenyl complexes [(eta(5)-C9H7)(dppm)Ru](2)(mu-CH=CH(C6H4)(n)CH=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