“Doping” of Polyyne with an Organometallic Fragment Leads to Highly Conductive Metallapolyyne Molecular Wire

Exploration
of highly conductive molecules is essential to achieve
single-molecule electronic devices. The present paper describes the
results on single-molecule conductance study of polyyne wires doped
with the organometallic Ru­(dppe)2 fragment, X(CC)nRu­(dppe)2(CC)nX. The metallapolyyne wires end-capped
with the gold fragments (X = AuL) are subjected to single-molecule
conductance measurements with the STM break junction technique, which
reveal the high conductance (10–3–10–2 G0; n = 2–4) with the low attenuation factor (0.25 Å–1) and the low contact resistance (33 kΩ). A unique “‘doping’”
effect of Ru­(dppe)2 fragment was found to lead to the high
performance as suggested by the hybrid density functional theory-nonequilibrium
green function calculation.