Electronic transport through ruthenium-based redox-active molecules in metal-molecule-metal nanogap junctions.
Electronic transport through ruthenium-based redox-active organometallic molecules is measured by self-assembling diruthenium(III) tetra(2-anilinopyridinate)-di(4-thiolphenylethynyl) (trans-Ru2(ap)4(C'CC6H4S-)2 (A) and trans- Ru2(ap)4((C'CC6H4)2S-)2 (B) molecules in nanogap molecular junctions. Voltage sweeps at a high scan rate show low bias current peaks (at +/-0.35 +/- 0.05 V for A and +/-0.27 +/- 0.05 V for B), which change to plateaus in slow bias scans and a second conductance peak at approximately +/-1.05 +/- 0.15 V. The peaks/plateaus are not observed in the return bias sweeps, possibly due to charge storage in the molecules. The energy states for the molecular orbitals of these molecules as estimated from the conductance peaks are in close agreement with the respective energy values from voltammetric measurements in solution.
Mahapatro
Ajit K
AK
Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
Ying
Jiewen
J
Ren
Tong
T
Janes
David B
DB