Current-voltage (I-V) characteristics for metal-molecule-metal junctions formed from three classes of molecules measured with a simple crossed-wire molecular electronics test-bed are reported. Junction conductance as a function of molecular structure is consistent with I-V characteristics calculated from extended Hückel theory coupled with a Green's function approach, and can be understood on the basis of bond-length alternation.

To investigate the electrical characteristics of organometallic complexes as molecular conductors, organometallic pi-conjugated molecules of the type trans-[PtL2(CCC6H4SAc-4)2], where L = PCy3, PBu3, PPh3, P(OEt)3, P(OPh)3, were synthesized and characterized by NMR, IR, UV, and X-ray spectroscopies. For the three complexes (L = PCy3, PPh3, and P(OEt)3) that could be measured using a cross-wire junction technique, the current-voltage (I-V) characteristics of a molecular monolayer of these complexes showed no ligand effect, despite spectroscopic evidence that electronic interaction between the phosphine ligands and the pi-system does occur. It was concluded that the tunneling efficiency across the molecule is the determining factor for conduction in this metal-molecule-metal system. It was also shown that the incorporation of a transition metal in pi-conjugated molecular wires does not adversely affect charge transport compared to all-carbon pi-conjugated molecular wires.

We demonstrate the ability to tune the current rectification in metal–molecule–metal junctions through control of the interaction strength of one of the two metal–molecule contacts. Current–voltage characteristics of thiolate bound molecular wires with a nitro or pyridine termination show that the extent of current rectification in a molecular junction correlates well with the extent of coupling between the chemical linker and metal electrode.

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We describe a new method for depositing patterned materials, based on non‐covalent trapping of ligands in solvent‐templated nanocavities created in aromatic, self‐assembled monolayer or polymer films. A model has been developed and tested to describe nanocavity formation and the ligand adsorption process, which occurs via ligand exclusion from ambient, aqueous solution into the hydrophobic nanocavities. Ligand adsorption rates and ligand adsorbate reactivity with solution species are governed by ligand size/geometry design factors identified using the model. Spatial control of adsorption is achieved via film photochemical changes that inhibit subsequent ligand adsorption/accessibility (UV or X‐ray) or displacement of entrapped ligands (50 keV electron‐beam) during film patterning. The reactivity of the adsorbed ligand is illustrated by the selective binding of PdII species that catalyze electroless metal deposition. Fabrication of high‐resolution (≈ 50 nm), positive‐tone patterns in nickel with acceptable feature‐edge acuity and critical dimension control (≈ 5 %) is demonstrated.