A Highly NIR Emissive Cu16Pd1 Nanocluster

Abstract

AbstractThe construction of stable copper nanoclusters (Cu‐NCs) with near‐infrared (NIR) emission that can be used for catalysis is highly desired, yet remains a challenge. Herein, an atomically precise bimetallic Cu/Pd NC with a molecular formula of Cu16Pd1L10(PPh3)2(Pz)6 (Pz = 3,5‐(CF3)2Pyrazolate, L = 4‐CH3OPhC≡C−), abbreviated as Cu16Pd1, is synthesized. Single‐crystal X‐ray crystallographic analysis of Cu16Pd1 reveals a Cu10Pd1 kernel with pseudo‐gyroelongated square bipyramid confirmation surrounded by other 6 Cu(I) ions and protected ligands. Interestingly, it exhibits strong NIR emission with the highest photoluminescence quantum yield (PLQY) among all the Cu NCs/Cu alloys (λem > 800 nm) in the solid‐state, and also displays NIR emission in solution. Experimental results and theoretical calculations suggest that the impressive NIR emission is attributed to abundant supramolecular interactions in the solid‐state, including intramolecular metal–metal and intermolecular interactions. Of note, the bimetallic Cu16Pd1 can catalyze the reduction of 4‐nitrophenol. This work provides a novel method for synthesizing Cu/Pd NCs and reminds that the less studied Cu/Pd NC can serve as outstanding luminescent material, which is seldom noticed in atomically precise nanoclusters.