Synthesis, Electrochemistry, and Single-Molecule Conductance of Bimetallic 2,3,5,6-Tetra(pyridine-2-yl)pyrazine-Based Complexes

Davidson, R.; Liang, J.H.; Milan, D.C.; Mao, B.W.; Nichols, R.J.; Higgins, S.J.; Yufit, D.S.; Beeby, A.; Low, P.J.

doi:10.1021/acs.inorgchem.5b00507

Synthesis, Electrochemistry, and Single-Molecule Conductance of Bimetallic 2,3,5,6-Tetra(pyridine-2-yl)pyrazine-Based Complexes

Davidson, R.; Liang, J.H.; Milan, D.C.; Mao, B.W.; Nichols, R.J.; Higgins, S.J.; Yufit, D.S.; Beeby, A.; Low, P.J.

Authors

R. Davidson

J.H. Liang

D.C. Milan

B.W. Mao

R.J. Nichols

S.J. Higgins

D.S. Yufit

Professor Andrew Beeby andrew.beeby@durham.ac.uk
Professor

P.J. Low

Abstract

The ligands 4′-(4-(methylthio)phenyl)-2,2′:6′,2″-terpyridine (L1), 4′-((4-(methylthio)phenyl)ethynyl)- 2,2′:6′,2″-terpyridine (L2), and bis(tridentate) bridging ligand 2,3,5,6-tetra(pyridine-2-yl)pyrazine (tpp) were used to prepare the complexes [Ru(L1)2][PF6]2 ([1][PF6]2, [Ru(L2)2][PF6]2 ([2][PF6]2), [{(L1)Ru}(μ-tpp){Ru(L1)}][PF6]4 ([3][PF6]4), and [{(L2)Ru}(μ-tpp){Ru(L2)}][PF6]4 ([4][PF6]4). Crystallographically determined structures give S···S distances of up to 32.0 Å in [4]4+. On the basis of electrochemical estimates, the highest occupied molecular orbitals of these complexes fall between −5.55 and −5.85 eV, close to the work function of clean gold (5.1–5.3 eV). The decay of conductance with molecular length across this series of molecules is approximately exponential, giving rise to a decay constant (pseudo β-value) of 1.5 nm–1, falling between decay factors for oligoynes and oligophenylenes. The results are consistent with a tunnelling mechanism for the single-molecule conductance behavior.

Citation

Davidson, R., Liang, J., Milan, D., Mao, B., Nichols, R., Higgins, S., …Low, P. (2015). Synthesis, Electrochemistry, and Single-Molecule Conductance of Bimetallic 2,3,5,6-Tetra(pyridine-2-yl)pyrazine-Based Complexes. Inorganic Chemistry, 54(11), 5487-5494. https://doi.org/10.1021/acs.inorgchem.5b00507

Journal Article Type	Article
Online Publication Date	May 14, 2015
Publication Date	Jun 1, 2015
Deposit Date	Apr 15, 2016
Publicly Available Date	May 14, 2016
Journal	Inorganic Chemistry
Print ISSN	0020-1669
Electronic ISSN	1520-510X
Publisher	American Chemical Society
Peer Reviewed	Peer Reviewed
Volume	54
Issue	11
Pages	5487-5494
DOI	https://doi.org/10.1021/acs.inorgchem.5b00507

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Copyright Statement
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.inorgchem.5b00507.