The Planar Si(IV) of Bis(catecholato)silane on a Metal Surface Induced by a Surface Constraint

• Published in: Journal of physical chemistry. C Vol. 129; no. 4; pp. 2020 - 2027
• Main Authors: Liu, Peizhen, Zhang, Tiantong, Zhang, Jinyu, Wang, Peichao, Wang, Hongchao, Han, You, Zhao, Dongbing, Gao, Hong-Ying
• Format: Journal Article
• Language: English
• Published: American Chemical Society 30.01.2025
• Subjects: C: Chemical and Catalytic Reactivity at Interfaces
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.4c07936

The structure of bis­(catecholato)­silane has been subject to debate, as to whether it is its tetrahedral or planar Si­(IV). To tackle the discussion, here, the bis­(catecholato)­silane molecules with visible molecular-level images on different metal surfaces are investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) simulations. It is found that the bis­(catecholato)­silane shows a tetrahedral Si­(IV) structure on both Au(111) and Ag(111) surfaces, while the bis­(catecholato)­silane can show a nearly planar Si­(IV) structure on the Cu(111) surface due to the strong interaction between the SiO4 moiety and the metal surface. Naturally, the conformational difference results in the self-assembly and on-surface chemistry behaving differently. Furthermore, the coverage of bis­(catecholato)­silane influences the self-assembly structures, indicating that the interactions among organic molecules affect the molecular tetrahedral or planar conformations. Our study reveals fundamental knowledge of the bis­(catecholato)­silane molecules on a surface, especially the tetrahedral or planar Si­(IV) selectivity influenced by the surface constraint.