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Probing pi-coupling in molecular junctions.

ABSTRACT: Charge transport characteristics for metal-molecule-metal junctions containing two structurally related pi-conjugated systems were studied to probe pi-pi interactions in molecular junctions. The first molecule contains a typical pi-conjugated framework derived from phenylene vinylene units, whereas the second has the phenylene vinylene structure interrupted by a [2.2]paracyclophane (pCp) core. Electrochemical investigations were used to characterize the defects and packing density of self-assembled monolayers of the two molecules on gold surfaces and to enable quantitative comparison of their transport characteristics. Current-voltage measurements across molecular junctions containing the two species demonstrate that the pCp moiety yields a highly conductive break in through-bond pi-conjugation. The observed high conductivity is consistent with density functional theory calculations, which demonstrate strong through-space pi-pi coupling across the pCp moiety.

SUBMITTER: Seferos DS

PROVIDER: S-EPMC1157018 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature

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Probing pi-coupling in molecular junctions.

Seferos Dwight S DS Trammell Scott A SA Bazan Guillermo C GC Kushmerick James G JG

Proceedings of the National Academy of Sciences of the United States of America 20050614 25

Charge transport characteristics for metal-molecule-metal junctions containing two structurally related pi-conjugated systems were studied to probe pi-pi interactions in molecular junctions. The first molecule contains a typical pi-conjugated framework derived from phenylene vinylene units, whereas the second has the phenylene vinylene structure interrupted by a [2.2]paracyclophane (pCp) core. Electrochemical investigations were used to characterize the defects and packing density of self-assemb ...[more]

PMID: 15956193

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