Ligand effects on charge transport in platinum(II) acetylides

Terence L Schull; James G Kushmerick; Charles H Patterson; Clifford George; Martin H Moore; Steven K Pollack; Ranganathan Shashidhar

doi:10.1021/ja029564o

Ligand effects on charge transport in platinum(II) acetylides

J Am Chem Soc. 2003 Mar 19;125(11):3202-3. doi: 10.1021/ja029564o.

Authors

Terence L Schull¹, James G Kushmerick, Charles H Patterson, Clifford George, Martin H Moore, Steven K Pollack, Ranganathan Shashidhar

Affiliation

¹ Center for Bio/Molecular Science and Engineering, Laboratory for the Structure of Matter, Naval Research Laboratory, Washington, DC 20375, USA. schull@nrl.navy.mil

PMID: 12630861
DOI: 10.1021/ja029564o

Abstract

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.