Tetrathiafulvalenes as anchors for building highly conductive and mechanically tunable molecular junctions

Qi Zhou; Kai Song; Guanxin Zhang; Xuwei Song; Junfeng Lin; Yaping Zang; Deqing Zhang; Daoben Zhu

doi:10.1038/s41467-022-29483-2

Tetrathiafulvalenes as anchors for building highly conductive and mechanically tunable molecular junctions

Nat Commun. 2022 Apr 4;13(1):1803. doi: 10.1038/s41467-022-29483-2.

Authors

Qi Zhou^#^{1

2}, Kai Song^#¹, Guanxin Zhang^{3

4}, Xuwei Song^{1

2}, Junfeng Lin^{1

2}, Yaping Zang^{5

6}, Deqing Zhang^{1

2}, Daoben Zhu¹

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, China.
² University of Chinese Academy of Sciences, 100049, Beijing, China.
³ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, China. gxzhang@iccas.ac.cn.
⁴ University of Chinese Academy of Sciences, 100049, Beijing, China. gxzhang@iccas.ac.cn.
⁵ Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, China. zangyaping@iccas.ac.cn.
⁶ University of Chinese Academy of Sciences, 100049, Beijing, China. zangyaping@iccas.ac.cn.

^# Contributed equally.

Abstract

The interface between molecules and electrodes has great impact on charge transport of molecular devices. Precisely manipulating the structure and electronic coupling of electrode-molecule interface at a molecular level is very challenging. Here, we develop new molecular junctions based on tetrathiafulvalene (TTF)-fused naphthalene diimide (NDI) molecules which are anchored to gold electrodes through direct TTF-Au contacts formed via Au-S bonding. These contacts enable highly efficient orbital hybridization of gold electrodes and the conducting π-channels, yielding strong electrode-molecule coupling and remarkably high conductivity in the junctions. By further introducing additional thiohexyl (SHe) anchors to the TTF units, we develop molecular wires with multiple binding sites and demonstrate reversibly switchable electrode-molecule contacts and junction conductance through mechanical control. These findings show a superb electrode-molecule interface and provide a new strategy for precisely tunning the conductance of molecular devices towards new functions.