Size Control of On-Surface Self-Assembled Nanochains Using Soft Building Blocks

• Published in: The journal of physical chemistry letters 2023-12, Vol.14 (50), p.11324-11332
• Main Authors: Song, Yang, Li, Zhanbo, Tang, Rongyu, Zhou, Kun, Zhang, Lizhi, Lin, Tao, Fan, Jian, Shi, Ziliang, Ma, Yu-Qiang
• Format: Article
• Language: English
• Subjects: Physical Insights into Chemistry, Catalysis, and Interfaces
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.3c02858

Owing to their conformational flexibility, soft molecules with side chains play a crucial role in molecular self-assembly or self-organization processes toward bottom-up building of supramolecular nanostructures. However, the influence of the rotating side chains in the confined space and subsequent surface-confined supramolecular self-assembly remains rarely explored. Herein, using the spatial confinement effect between soft building blocks, we realized size control on surface-confined supramolecular coordination self-assembly through the synergy between the repulsive steric hindrance and the attractive chemical interactions. Combining scanning tunneling microscopy with density functional theory calculations and Monte Carlo simulations, we elucidated the effective repulsive force generated by the thermal wiggling motions of the soft building blocks, allowing length tuning of the self-assembled chain structures. Through a delicate balance between the repulsive interaction induced by the spatial confinement effect and the coordinate chemical interaction, we provide a new strategy for controlling the geometry of the on-surface supramolecular nanostructures.