Organometallic molecular wires as versatile modules for energy-level alignment of the metal–molecule–metal junction

The organometallic Ru molecular wires 1–3 Ru(PR3)4(CCC5H5N)2 [(PR3)4 = (dppe)2 (1), [P(OMe3)]4 (2), and (dmpe)2 (3)] show significantly higher conductance compared to their organic counterpart, 1,4-dipyridyl butadiyne (4). CV and UV-Vis measurements and DFT calculations suggest that the high-lying HOMOs of the Ru wires are the key factor for the high conductance.