Nitrile ligands for controlled synthesis of alkynyl-ruthenium based homo and hetero bimetallic systems

Wire like mono- and poly-nuclear molecules based on alkynyl ruthenium complexes whose core unit is trans-[Ru(Ctriple bond; length of mdashC-R)(R′Ctriple bond; length of mdashN)(dppe)2][PF6] are readily formed in soft conditions. The electronic dual character of the metallic unit, donor through the acetylide moiety, acceptor versus the nitrile ligand is exemplified through electrochemical studies of a series of ethynylferrocene and cyanoferrocene derivatives. A single crystal X-ray diffraction analysis of the [(dppe)2(PhCtriple bond; length of mdashC)Ru(Ntriple bond; length of mdashC-C6H4-Ctriple bond; length of mdashN)Ru(Ctriple bond; length of mdashCPh)(dppe)2][2PF6] bimetallic complex 5 shows that the global structure of such complexes consists of wire type dimetallic units. With the availability of this versatile, direct, and simple route, a new class of extended rigid rod systems of nanometric size with multilevel electron transfers is readily accessed.