Atomically precise copper nanoclusters and their applications

Although Cu nanoparticles (CuNPs) have been subjected to broad investigations, especially viewing their easy access, low cost and rich catalytic properties, atomically precise copper nanoclusters (CuNCs) are less often examined due to the difficulties of their isolation in pure form. Yet their study is essential for a better understanding of the molecular, physical and catalytic properties of CuNPs that are in fact mixtures of CuNCs. The review highlights the background and recent progress in CuNCs including the structural and physico-chemical properties and new applications to galvanic reactions, fluorescence and catalysis. Particular emphasis is placed on catalysis for which hydrogen evolution reaction, reduction of CO2 and recent comparative results from our group concerning 1,3-dipolar cycloaddition of organic azides and alkynes (CuAAC, click reaction) are detailed. In this latter sub-field the key role of the relative stabilities of the CuNCs on their performances is emphaSized as shown with Clayborne and Chen's nanocluster anion [Cu-6(SR)(6)](-) [Na+, solvent], R = C7H4NO, solvent = acetone or THF, that shows excellent efficiency for the CuAAC reaction. (C) 2018 Elsevier B.V. All rights reserved.