Electrical conductance study on 1,3-butadiyne-linked dinuclear ruthenium(ii) complexes within single molecule break junctions

Abstract

Single-molecule conductance of three sulphur-functionalized organometallic wires with two ruthenium(II) centres spaced by 1,3-butadiyne was firstly investigated using an electrochemically assisted-mechanically controllable break junction (EC-MCBJ) approach. It is demonstrated that single-molecular conductance of these diruthenium(II) incorporated systems is significantly higher than oligo(phenylene-ethynylene) (OPE) having comparable lengths and exhibits weaker length dependence. The conductance improvement in these diruthenium(II) molecules is ascribable to the better energy match of the Fermi level of gold electrodes with the HOMO that is mainly resident on the Ru-C^C-C^C-Ru backbone.Furthermore, modulation of molecular conductance is achieved by changing the length and pconjugated system of the chelating 2,2 0 :6 0 ,2 00 -terpyridyl ligand.

Ferrocene‐Alkynyl Conjugated Molecular Wires: Synthesis, Characterization, and Conductance Properties

“…Furthermore,t he linear correlation between current intensity (i pa or i pc )a nd the scan rate demonstrated that wire a1 indeed self-assembled onto the gold electrode surface (Figure 3a). The surface coverage [37] of wire a1 estimatedf rom the charge of the anodic peak around1 00 mV s À1 is 1.28 10 À10 mol cm À2 ,w hichi sc omparable to the Fc-CC-C 6 H 4 -SAc [24] monolayer with as ingle anchoring group (1.24 10 À10 mol cm À2 ). In addition to the linear conformation of wire a1,w ec onclude that wire a1 is adsorbed onto the gold surfacet hrough single AuÀSb ondingr ather than lying flat on the surface.…”

Electron‐Transfer Kinetics in Polymetallic Carbon‐Rich Ruthenium(II) Bis(σ‐arylacetylides) Wires Connected to Gold

“…[5] In this direction, molecularw ires of various lengths have been obtained by connecting metal complexes to form linear polymetallic assemblies, in particular,w ith iron or ruthenium complexeso rw ith ac ombination of the two. [6][7][8][9][10][11][12][13][14][15] Af osteringm otivation of this research is also the fine tuning of the electron transportt hrough molecules with ap ertinent design of molecular architectures to performl ogical functions usually operated by semiconducting devices, [16] that is, to ideally providem ultibitm emory systems with lowp ower consumption. In this respect, chemicals tability in different oxidation states, (multiple) electron-transfer eventsa ssociated with low redox potentials, and fast electron-transfer kinetics are highly desirable properties for efficient information processing at the shortestt imescale.…”

Single Gold Atom Containing Oligo(phenylene)ethynylene: Assembly into LB Films and Electrical Characterization

“…[13][14] The introduction of pendant moieties, 15 or changes to the nature of the arylene fragment to modulate quantum interference pathways, 16 permits the assembly of wire-like molecules of a wide range of lengths [17][18] that are synthetically compatible with a diverse range of surface contacting groups. [19][20][21] The conductance of the OPE scaffold can also be modulated through the introduction of metal centers [22][23][24][25][26][27][28][29] or metallocene [30][31] fragments within this -conjugated pathway, which augments a fast growing area of study concerning metal coordination complexes as components in molecular electronics. [32][33][34][35][36][37][38][39][40][41][42] To date, the vast majority of metal compounds and complexes studied within metal|molecule|metal junctions or related sandwich structures formed by contacting monolayer films have been based on the Group 8, 9 and 10 metals, for reasons of synthetic availability and redox activity, in an axiallysubstituted arrangement within the wire-like assembly.…”