Single-Molecule Conductance Behavior of Molecular Bundles

Bara-Estaún, Alejandro; Planje, Inco J.; Almughathawi, Renad; Naghibi, Saman; Vezzoli, Andrea; Milan, David C.; Lambert, Colin; Martin, Santiago; Cea, Pilar; Nichols, Richard J.; Higgins, Simon J.; Yufit, Dmitry S.; Sangtarash, Sara; Davidson, Ross J.; Beeby, Andrew

Abstract

Controlling the orientation of complex molecules in molecular junctions is crucial to their development into functional devices. To date, this has been achieved through the use of multipodal compounds (i.e., containing more than two anchoring groups), resulting in the formation of tri/tetrapodal compounds. While such compounds have greatly improved orientation control, this comes at the cost of lower surface coverage. In this study, we examine an alternative approach for generating multimodal compounds by binding multiple independent molecular wires together through metal coordination to form a molecular bundle. This was achieved by coordinating iron(II) and cobalt(II) to 5,5′-bis(methylthio)-2,2′-bipyridine (L1) and (methylenebis(4,1-phenylene))bis(1-(5-(methylthio)pyridin-2-yl)methanimine) (L2) to give two monometallic complexes, Fe-1 and Co-1, and two bimetallic helicates, Fe-2 and Co-2. Using XPS, all of the complexes were shown to bind to a gold surface in a fac fashion through three thiomethyl groups. Using single-molecule conductance and DFT calculations, each of the ligands was shown to conduct as an independent wire with no impact from the rest of the complex. These results suggest that this is a useful approach for controlling the geometry of junction formation without altering the conductance behavior of the individual molecular wires.

Citation

Bara-Estaún, A., Planje, I. J., Almughathawi, R., Naghibi, S., Vezzoli, A., Milan, D. C., …Beeby, A. (2023). Single-Molecule Conductance Behavior of Molecular Bundles. Inorganic Chemistry, 62(51), 20940-20947. https://doi.org/10.1021/acs.inorgchem.3c01943

• Journal Article Type: Article
• Acceptance Date: Nov 27, 2023
• Online Publication Date: Dec 11, 2023
• Publication Date: Dec 25, 2023
• Deposit Date: Jan 17, 2024
• Publicly Available Date: Jan 17, 2024
• Journal: Inorganic Chemistry
• Print ISSN: 0020-1669
• Electronic ISSN: 1520-510X
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 62
• Issue: 51
• Pages: 20940-20947
• DOI: https://doi.org/10.1021/acs.inorgchem.3c01943
• Keywords: Inorganic Chemistry; Physical and Theoretical Chemistry
• Public URL: https://durham-repository.worktribe.com/output/2149389