Highly conducting single-molecule topological insulators based on mono- and di-radical cations

Li L, Low JZ, Wilhelm J, Liao G, Gunasekaran S, Prindle CR, Starr RL, Golze D, Nuckolls C, Steigerwald ML, Evers F, Campos LM, Yin X, Venkataraman L (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Nature Chemistry Nature Publishing Group

Book Volume: 14

Pages Range: 1061-1067

Journal Issue: 9

DOI: 10.1038/s41557-022-00978-1

Abstract

Single-molecule topological insulators are promising candidates as conducting wires over nanometre length scales. A key advantage is their ability to exhibit quasi-metallic transport, in contrast to conjugated molecular wires which typically exhibit a low conductance that decays as the wire length increases. Here, we study a family of oligophenylene-bridged bis(triarylamines) with tunable and stable mono- or di-radicaloid character. These wires can undergo one- and two-electron chemical oxidations to the corresponding mono-cation and di-cation, respectively. We show that the oxidized wires exhibit reversed conductance decay with increasing length, consistent with the expectation for Su–Schrieffer–Heeger-type one-dimensional topological insulators. The 2.6-nm-long di-cation reported here displays a conductance greater than 0.1G0, where G0 is the conductance quantum, a factor of 5,400 greater than the neutral form. The observed conductance–length relationship is similar between the mono-cation and di-cation series. Density functional theory calculations elucidate how the frontier orbitals and delocalization of radicals facilitate the observed non-classical quasi-metallic behaviour. [Figure not available: see fulltext.]

Involved external institutions

Columbia University US United States (USA) (US) Universität Regensburg DE Germany (DE) Beijing Institute of Technology (BIT) / 北京理工大学 CN China (CN) Technische Universität Dresden DE Germany (DE)

How to cite

APA:

Li, L., Low, J.Z., Wilhelm, J., Liao, G., Gunasekaran, S., Prindle, C.R.,... Venkataraman, L. (2022). Highly conducting single-molecule topological insulators based on mono- and di-radical cations. Nature Chemistry, 14(9), 1061-1067. https://doi.org/10.1038/s41557-022-00978-1

MLA:

Li, Liang, et al. "Highly conducting single-molecule topological insulators based on mono- and di-radical cations." Nature Chemistry 14.9 (2022): 1061-1067.

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