Innentitelbild: Reactivities of Interstitial Hydrides in a Cu₁₁ Template: En Route to Bimetallic Clusters (Angew. Chem. 2/2022)

Abstract

In sharp contrast to that of surface hydrides, reactivities on interstitial hydrides are difficult to explore. When treated with a metal ion (Cu + , Ag + , and Au + ), the stable Cu(I) dihydride template [Cu11H2{S2P(O i Pr)2}6(C≡CPh)3] (H2Cu11) generates surprisingly three very different compounds; namely(2), and [AuCu11{S2P(O i Pr)2}6(C≡CPh)3Cl] (3). 1 and 2 are both M(I) 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 an AgCu3 environment of 2. The bimetallic cluster of 3 has no hydride and exhibits a mixed-valent [AuCu11] 10+ metal core, making it a 2-electron superatom. Thus, depending on the nature of M + , trigonal pyramidal hydrides of the H2Cu11 reactant behave differently. In the cases of M = Cu or Ag, they act as regular 2-electron ligands. In the case of M = Au, they behave as electron donors, leading to the formation of a 2-electron superatom, with liberation of H2.. .

Hydride‐containing 2‐Electron Pd/Cu Superatoms as Catalysts for Efficient Electrochemical Hydrogen Evolution

“…Owing to the important contribution of the metal valence s (and, to a lesser extent, p) AOs in this HOMO and its spheroidal shape, it can be identified as a superatomic 1S orbital. It is actually quite similar to the 1S HOMO of the structurally related AuCu 11 , [22] and by consequence to the HOMO of the ideally cuboctahedral [MCu 12 {dtc/dtp} 6 (C≡CPh) 6 ] + (M=Cu, Ag, Au) clusters [24, 25] . Considering all these species as being 2‐electron superatoms with 1S 2 1P 0 configuration stresses the role of the encapsulated hydride in PdHCu 11 .…”

“…Replacing, in this latter cluster, the C�CPh ligand connected to Pd by Cl generates a 2electron cluster very similar to the known AuCu 11 . [22] Among these two anionic models of 1S 2 1P 0 configuration, the latter has its 1P x , 1P y and 1P z orbitals close in energy and lying among the lowest unoccupied levels, as for AuCu 11 [22] and the [MCu 12 {dtc/dtp} 6 (C�CPh) 6 ] + (M = Cu, Ag, Au) clusters. [24,25] This is not the case for the former model [PdCu 11 (S 2 PH 2 ) 6 (C�CPh) 4 ] À , for which the 1P z orbital (z-axis along the PdÀ C bond) is found higher in energy due to its destabilization by the C�CPh ligand.…”

“…Herein first hydride-containing 2-electron palladium/ copper superatomic alloys co-protected by alkynyl and dithiophosphato ligands are prepared by the treatment of PdH 2 Cu 14 [17] with trifluoroacetic acid (TFA Lewis bases, reducing Pd II to Pd 0 and supplying the hydride ligand in PdHCu 11 . [22,23] Presumably, an aggregation occurs during the reaction, which leads to the addition of one alkynyl ligand in the yielded alloy cluster. Alternatively, PdHCu 11 can also be synthesized by the addition of two equiv.…”

Recent progress in dichalcophosphate coinage metal clusters and superatoms

“…93 Copper( 9). 94 Interestingly, these reactions trigger the reactivity of the interstitial m 4 -hydrides of the Cu 11 H 2 cluster, making them react like Lewis bases or reductants. To our knowledge, the interstitial hydrides behaving as Lewis bases have never been observed in heterometallic clusters.…”

Chiral Alkynyl‐Stabilized Ag/Cu Nanoclusters from Spontaneous Resolution

“…The distances between Ag atoms on (PET is 2-phenylethanethiolate), [11] [Cu 25 H 10 (SPhCl 2 ) 18 ] 3À [12] and [Cu 11 H 2 {S 2 P(O i Pr) 2 } 6 (C�CPh) 3 ]. [13] This is also a nice indication of strong interaction between Cu atoms in the ring. Within the Ag 6 Cu core, the average AgÀ Cu distance is 2.940 Å, while that within the ring is 2.692 Å.…”