Conductance Evolution of Photoisomeric Single-Molecule Junctions under Ultraviolet Irradiation and Mechanical Stretching

• DOI: 10.1021/jacs.3c13752
• Publication Date: 2024-02-28T01:35:52Z
• Authors: Min Tan; Feng Sun; Xueyan Zhao; Zhibin Zhao; Surong Zhang; Xiaona Xu; Adila Adijiang; Wei Zhang; Haoyu Wang; Chuankui Wang; Zongliang Li; Elke Scheer; Dong Xiang
• Keywords: Azobenzene; Molecular switch; Molecular wire; Break junction; Conformational change; Photoswitch

A comprehensive understanding of carrier transport in photoisomeric molecular junctions is crucial for the rational design and delicate fabrication single-molecule functional devices. It has been widely recognized that conductance azobenzene (a class molecules) based mainly determined by photoinduced conformational changes. In this study, it demonstrated most probable amine-anchored azobenzene-based increases continuously upon UV irradiation. contrast, pyridyl-anchored with an identical core exhibits a contrasting trend, highlighting pivotal role anchoring groups play, potentially overriding (even reversing) effects further molecule cis-conformation cannot be fully mechanically stretched into trans-conformation, clarifying great challenge to realize reversible switch purely mechanical operation. Additionally, revealed coupling strength molecules dramatically weakened when irradiation time prolonged, whereas not observed molecules. The mechanisms these observations are elucidated assistance density theory calculations UV–Vis spectra combined flicker noise measurements which confirm changes, providing insight charge offering routine logical designing synchro opto-mechanical switches.