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In sharp contrast to surface hydrides, reactivities of interstitial hydrides are difficult to explore. When treated with a metal ion (Cu+, Ag+, and Au+), the stable CuI dihydride template [Cu11H2{S2P(OiPr)2}6(C≡CPh)3] (H2Cu11) generates surprisingly three very different compounds, namely [CuH2Cu11{S2P(OiPr)2}6(C≡CPh)3]+ (1), [AgH2Cu14{S2P(OiPr)2}6((C≡CPh)6]+ (2), and [AuCu11{S2P(OiPr)2}6(C≡CPh)3Cl] (3). Compounds 1 and 2 are both MI species and maintain the same number of hydride ligands as their H2Cu11 precursor. Neutron diffraction revealed the first time a trigonal‐pyramidal hydride coordination mode in the AgCu3 environment of 2. 3 has no hydride and exhibits a mixed‐valent [AuCu11]10+ metal core, making it a two‐electron superatom. [ABSTRACT FROM AUTHOR]

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), [Cu30H18{S2P(OnPr)2}12] (1H), fully characterized by various spectroscopic methods and single‐crystal X‐ray diffraction. The X‐ray structure of 1H reveals an unprecedented central Cu12 hollow icosahedron. Six faces of this icosahedron are capped by Cu3 triangles, the whole Cu30 core being wrapped by twelve dithiophosphate ligands and the whole cluster has ideal S6 symmetry. The locations of the 18 hydrides in 1H were ascertained by a single‐crystal neutron diffraction study. They are composed of three types: capping μ3‐H, interstitial μ4‐H (seesaw) and μ5‐H ligands (square pyramidal), in good agreement with the DFT simulations. The numbers of hydrides and ligand resonances in the 1H NMR spectrum of 1H are in line with their coordination environment in the solid state, retaining the S6 symmetry in solution. Furthermore, two new Se‐protected polyhydrido copper nanoclusters, [Cu30H18{Se2P(OR)2}12] (2H: R=iPr 3H: R=iBu) were synthesized from their sulfur relative 1H 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 1H–3H. In addition, the reaction of 1H with [Pd(PPh3)2Cl2] in the presence of terminal alkynes led to the formation of new bimetallic Cu−Pd alloy clusters [PdCu14H2{S2P(OnPr)2}6(C≡CR)6] (4: R=Ph; 5: R=C6H4F). [ABSTRACT FROM AUTHOR]

The structurally precise Cu‐rich hydride nanoclusters [PdCu14H2(dtc/dtp)6(C≡CPh)6] (dtc: di‐butyldithiocarbamate (1); dtp: di‐isopropyl dithiophosphate (2)) were synthesized from the reaction of polyhydrido copper clusters [Cu28H15(S2CNnBu2)12]+ or [Cu20H11{S2P(OiPr)2}9] with phenyl acetylene in the presence of Pd(PPh3)2Cl2. Their structures and compositions were determined by single‐crystal X‐ray diffraction and the results supported by ESI‐mass spectrometry. Hydride positions in 1 were confirmed by single‐crystal neutron diffraction. Each hydride is connected to one Pd0 and four CuI atoms in slightly distorted trigonalbipyramidal geometry. The anatomies of clusters 1 and 2 are very similar and DFT calculations allow rationalizing the interactions between the encapsulated [PdH2]2− unit and its Cu14 bicapped icosahedral cage. As a result, Pd has the highest coordination number (14) so far recorded. Come in number 14: A unique methodology was used to synthesize atomically precise palladium‐alloyed copper hydride clusters. X‐ray and neutron diffraction revealed that a 14‐electron [PdH2]2− unit is iono‐covalently encapsulated within a bicapped icosahedral [Cu14]14+ cage and, as a result, the central Pd0 adopts the coordination number of 14. [ABSTRACT FROM AUTHOR]