Template-assisted synthesis of isomeric copper(i) clusters with tunable structures showing photophysical and electrochemical properties.

A comparative study of structure-property relationships in isomeric and isostructural atomically precise clusters is an ideal approach to unravel their fundamental properties. Herein, seven high-nuclearity copper(i) alkynyl clusters utilizing template-assisted strategies were synthesized. Spherical Cu 36 and Cu 56 clusters are formed with a [M@(V/PO 4 ) 6 ] (M: Cu 2+ , Na + , K + ) skeleton motif, while peanut-shaped Cu 56 clusters feature four separate PO 4 templates. Experiments and theoretical calculations suggested that the photophysical properties of these clusters are dependent on both the inner templates and outer phosphonate ligands. Phenyl and 1-naphthyl phosphate-protected clusters exhibited enhanced emission features attributed to numerous well-arranged intermolecular C-H⋯π interactions between the ligands. Moreover, the electrocatalytic CO 2 reduction properties suggested that internal PO 4 templates and external naphthyl groups could promote an increase in C 2 products (C 2 H 4 and C 2 H 5 OH). Our research provides new insight into the design and synthesis of multifunctional copper(i) clusters, and highlights the significance of atomic-level comparative studies of structure-property relationships.