Tuning the electrical conductance of metalloporphyrin supramolecular wires

Noori, Mohammed; Aragones, Albert C.; Di Palma, Giuseppe; Darwish, Nadium; Bailey, Steven W.D.; Al-Galiby, Quisy; Grace, Iain; Amabilino, David B.; Gonzalez-Campo, Ar�ntzazu; D�ez-P�rez, Ismael; Colin J., Lambert

Abstract

In contrast with conventional single-molecule junctions, in which the current flows parallel to the long axis or plane of a molecule, we investigate the transport properties of M(II)-5,15-diphenylporphyrin (M-DPP) single-molecule junctions (M=Co, Ni, Cu, or Zn divalent metal ions), in which the current flows perpendicular to the plane of the porphyrin. Novel STM-based conductance measurements combined with quantum transport calculations demonstrate that current-perpendicular-to-the-plane (CPP) junctions have three-orders-of-magnitude higher electrical conductanc than their current in-plane (CIP) counterparts, ranging from 2.10?2 G0 for Ni-DPP up to 8.10?2 G0 for Zn-DPP. The metal ion in the center of the DPP skeletons is strongly coordinated with the nitrogens of the pyridyl coated electrodes, with a binding energy that is sensitive to the choice of metal ion. We find that the binding energies of Zn-DPP and Co-DPP are significantly higher than those of Ni-DPP and Cu-DPP. Therefore when combined with its higher conductance, we identify Zn-DPP as the favoured candidate for high conductance CPP single-molecule devices.

Citation

Noori, M., Aragones, A. C., Di Palma, G., Darwish, N., Bailey, S. W., Al-Galiby, Q., …Colin J., L. (in press). Tuning the electrical conductance of metalloporphyrin supramolecular wires. Scientific Reports, 6, Article 37352. https://doi.org/10.1038/srep37352

• Journal Article Type: Article
• Acceptance Date: Oct 21, 2016
• Online Publication Date: Nov 21, 2016
• Deposit Date: Dec 20, 2016
• Publicly Available Date: Dec 20, 2016
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Article Number: 37352
• DOI: https://doi.org/10.1038/srep37352
• Public URL: https://nottingham-repository.worktribe.com/output/827684
• Publisher URL: http://www.nature.com/articles/srep37352