Single-Molecule Conductance through an Isoelectronic B-N Substituted Phenanthrene Junction

Zhi-Hao Zhao; Lin Wang; Shi Li; Wei-Dong Zhang; Gang He; Dong Wang; Shi-Min Hou; Li-Jun Wan

doi:10.1021/jacs.0c00879

Single-Molecule Conductance through an Isoelectronic B-N Substituted Phenanthrene Junction

J Am Chem Soc. 2020 May 6;142(18):8068-8073. doi: 10.1021/jacs.0c00879. Epub 2020 Apr 28.

Authors

Zhi-Hao Zhao^{1

2}, Lin Wang³, Shi Li⁴, Wei-Dong Zhang⁵, Gang He⁵, Dong Wang^{1

2}, Shi-Min Hou⁴, Li-Jun Wan^{1

2}

Affiliations

¹ CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing National Laboratory for Molecular Science (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ School of Materials Science and Technology, University of Geosciences, Beijing 100083, China.
⁴ Key Laboratory for Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, China.
⁵ Frontier Institute of Science and Technology, State Key Laboratory for Strength and Vibration of Mechanical Structures, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710054, China.

PMID: 32321243
DOI: 10.1021/jacs.0c00879

Abstract

Single-molecule conductance of a B-N substituted phenanthrene derivative and its isoelectronic C═C counterpart was investigated by the scanning tunneling microscopy break junction (STM-BJ) technique. The incorporation of the B-N motif results in a better single-molecule conductivity than the C═C analogue. Furthermore, the Lewis acid-base reaction between F^- and the B atom of the B-N motif leads to a decrease of the conductance of the BN derivative, which can be understood due to the shifting of the energy positions of the LUMO, as revealed by quantum transport calculations, even though the HOMO-LUMO gap decreases in the B-F Lewis acid-base. These findings provide insights for modulating electron transport properties by isoelectronic structure design. The B-N isoelectronic substituted structure could be a feasible way to design single-molecule devices such as switches and chemical sensors.