Milling-Induced "Turn-off" Luminescence in Copper Nanoclusters.

Atomically precise copper nanoclusters (NCs) attract research interest due to their intense photoluminescence, which enables their applications in photonics, optoelectronics, and sensing. Exploring these properties requires carefully designed clusters with atomic precision and a detailed understanding of their atom-specific luminescence properties. Here, we report two copper NCs, [Cu(MNA)(DPPE)] and [Cu(MNA-H)], shortly Cu and Cu, protected by 2-mercaptonicotinic acid (MNA-H) and 1,2-bis(diphenylphosphino)ethane (DPPE), showing "turn-off" mechanoresponsive luminescence.

Multicolor photoluminescence of Cu clusters modulated using surface ligands.

Copper nanoclusters exhibit unique structural features and their molecular assembly results in diverse photoluminescence properties. In this study, we present ligand-dependent multicolor luminescence observed in a Cu cluster, primarily protected by -carborane-9,12-dithiol (-CBDT), featuring an octahedral Cu inner kernel enveloped by eight isolated copper atoms. The outer layer of the metal kernel consists of six bidentate -CBDT ligands, in which carborane backbones are connected through μ-sulphide linkages.