Planar Tetracoordinate Silicon in Si <sub>3</sub> Cu <sub>3</sub> <sup>−</sup> Cluster
Xiao-han Yin, Hong-lin Zeng, Xinbo Liu, Hong‐Guang Xu, Hong‐Guang Xu, Gabriel Merino, Wei‐jun Zheng, Zhong‐hua Cui
Abstract
Abstract Photoelectron spectroscopy and theoretical calculations have identified the global minimum structure of the 16‐valence electron Si 3 Cu 3 − cluster, which features a planar tetracoordinate silicon (ptSi) in a rhombic arrangement. The Si 3 and Cu 3 triangles are interconnected by a Si 2 /Cu 2 edge, forming an ordered chain‐like structure. Besides the conventional 2c–2e σ‐bond connecting Si 3 and Cu 3 , the stability of this cluster is reinforced by a delocalized 3c–2e σ‐bond in Cu 3 and a π‐bond in Si 3 . Our study provides experimental confirmation of a planar hypercoordinate heavier Group 14 element, opening possibilities for exploring similar structures in two‐dimensional materials.