Polyhydrido Copper Nanoclusters with a Hollow Icosahedral Core: [Cu H {E P(OR) } ] (E=S or Se; R=nPr, iPr or iBu).

Although atomically precise polyhydrido copper nanoclusters are of prime interest for a variety of applications, they have so far remained scarce. Herein, this work describes the synthesis of a dithiophosphate-protected copper(I) hydride-rich nanocluster (NC), [Cu H {S P(OnPr) } ] (1 ), fully characterized by various spectroscopic methods and single-crystal X-ray diffraction. The X-ray structure of 1 reveals an unprecedented central Cu hollow icosahedron. Six faces of this icosahedron are capped by Cu triangles, the whole Cu core being wrapped by twelve dithiophosphate ligands and the whole cluster has ideal S symmetry. The locations of the 18 hydrides in 1 were ascertained by a single-crystal neutron diffraction study. They are composed of three types: capping μ -H, interstitial μ -H (seesaw) and μ -H ligands (square pyramidal), in good agreement with the DFT simulations. The numbers of hydrides and ligand resonances in the H NMR spectrum of 1 are in line with their coordination environment in the solid state, retaining the S symmetry in solution. Furthermore, two new Se-protected polyhydrido copper nanoclusters, [Cu H {Se P(OR) } ] (2 : R=iPr 3 : R=iBu) were synthesized from their sulfur relative 1 via ligand displacement reaction and their X-ray structures feature the exceptional case where both the NC shape and size are fully conserved during the course of ligand exchange. DFT and TD-DFT calculations allow understanding the bonding and optical properties of clusters 1 -3 . In addition, the reaction of 1 with [Pd(PPh ) Cl ] in the presence of terminal alkynes led to the formation of new bimetallic Cu-Pd alloy clusters [PdCu H {S P(OnPr) } (C≡CR) ] (4: R=Ph; 5: R=C H F).