Noori, Mohammed and Aragonès, Albert and Di Palma, Giuseppe and Darwish, Nadim and Bailey, Steven William Dennis and Al-Galiby, Qusiy and Grace, Iain Mark and Amabilino, David B. and Gonzalez-Campo, Arantzazu and Díez-Pérez, Ismael and Lambert, Colin John (2016) Tuning the electrical conductance of metalloporphyrin supramolecular wires. Scientific Reports, 6 (37352): 37352. ISSN 2045-2322
Full text not available from this repository.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 conductances 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