Extending Metal-Capped Polyynediyl Molecular Wires by Insertion of Inorganic Metal Units
Résumé
Several symmetric and asymmetric bis(metalla-diynediyl)ruthenium(II) complexes of the general formula trans-{LxRu}C≡CC≡C{Ru(dppe)2}C≡CC≡C{RuL′y} (Lx, L′y = (PPh3)2Cp, (dppe)Cp, (dppe)Cp*), containing Ru(dppe)2 as the central linking group, have been successfully synthesized and characterized spectroscopically. DFT calculations show that their HOMO's are delocalized over the Ru-C4-Ru-C4-Ru chain, suggesting that there is electronic interaction between the terminal RuLx groups through the C4 chains and the Ru(dppe)2 center. Limited electrochemical measurements reveal that the complexes undergo a series of five stepwise reversible or quasi-reversible oxidation processes.