There have been considerable interests in the synthesis and characterization of dimeric and polymeric organometallic compounds with π-conjugated bridges, because of their promising structural, chemical and material properties. Dimeric complexes with linear C_nH_n bridges are interesting especially in the view that many conjugated organic materials (for example, polyacetylenes, push / pull stilbenes and polyenes) have only sp² carbons in their backbones. For these reasons, we have been interested in developing convenient synthetic methodology to diruthenium complexes containing linear C_nH_n bridges and novel π-conjugated carbon-rich bridges with metal-C(sp²) linkages....[ Read more ]

There have been considerable interests in the synthesis and characterization of dimeric and polymeric organometallic compounds with π-conjugated bridges, because of their promising structural, chemical and material properties. Dimeric complexes with linear C_nH_n bridges are interesting especially in the view that many conjugated organic materials (for example, polyacetylenes, push / pull stilbenes and polyenes) have only sp² carbons in their backbones. For these reasons, we have been interested in developing convenient synthetic methodology to diruthenium complexes containing linear C_nH_n bridges and novel π-conjugated carbon-rich bridges with metal-C(sp²) linkages.

In our research programme, hydrometallations of dialkynes to carbonyl hydrido complexes were authenticated to be very effective routes towards interesting bimetallic complexes, through which dinuclear complexes with C₄H₄- bridges were prepared. Further evolution of the methodology was extended to the manipulations of diacetylene with hydroxy-functionalities, particularly with the interest that a conjugated linkage could be established between the metallic centers via insertion of hydroxy-functionalized dialkynes followed by electrophilic abstraction of the hydroxy groups. Promising results were demonstrated by the successful preparations of dimeric complexes containing conjugated C₅H₅-bridges and vinylcarbene-bis(thiophene) =CHCH=CH(C₄H₂S)₂H=CHCH= linkages.

As bimetallic complexes are commendable model systems which allow examination of through-space and through-bond redox interactions between the two metallic centers, this research programme also focused on the electrochemical communication between the organometallic fragments across various bridging ligands in such kinds of complexes, and the effects on the inter-nuclear communication contributed by nature of hydrocarbon bridges and other ligands involved in the coordination sphere of the complexes.