Rod-Shaped Silver Supercluster Unveiling Strong Electron Coupling between Substituent Icosahedral Units

The first linear silver supercluster based on icosahedral Ag-13 units has been constructed via bridging of dpa ligands: Ag-61(dpa)(27)(SbF6)(4) (Hdpa = dipyridylamine) (Ag-61). Single-crystal X-ray diffraction reveals that this rod-shaped cluster consists of four vertex-sharing Ag-13 icosahedra in a linear arrangement. This Ag-61 cluster represents the longest one-dimensional metal nanocluster with a resolved structure. Unprecedented electron coupling develops between their constituent Ag-13 units. Theoretical studies disclose that the stabilities of the two superclusters are dictated by a strong interaction between the Ag-13 units as well as the ligand effect of the dpa-Ag motifs. The quantum size effect accounts for the significant enhancement of the metal-related absorptions and the red shift at the near-infrared region as the length of the cluster increases. This work sheds light on the evolution of one-dimensional materials and an understanding of the electronic communication between the constituent clusters.

Automated summary

This study presents the construction of a linear silver supercluster based on Ag-13 units and reveals its stability and electron coupling mechanism. The quantum size effect explains the enhancement of metal-related absorption intensity and the red shift phenomenon.