Reactivities of Interstitial Hydrides in a Cu₁₁ Template: En Route to Bimetallic Clusters

Abstract

In sharp contrast to surface hydrides,r eactivities of interstitial hydrides are difficult to explore.W hen treated with am etal ion (Cu + ,A g + ,a nd Au + ), the stable Cu I dihydride template [Cu 11 H 2 {S 2 P(O i Pr) 2 } 6 (C CPh) 3 ]( H 2 Cu 11 )g enerates surprisingly three very different compounds,n amely [CuH 2 Cu 11 {S 2 P(O i Pr) 2 } 6 (C CPh) 3 ] + (1), [AgH 2 Cu 14 {S 2 P-(O i Pr) 2 } 6 ((CCPh) 6 ] + (2), and [AuCu 11 {S 2 P(O i Pr) 2 } 6 (C CPh) 3 Cl] (3). Compounds 1 and 2 are both M I species and maintain the same number of hydride ligands as their H 2 Cu 11 precursor.Neutron diffraction revealed the first time atrigonalpyramidal hydride coordination mode in the AgCu 3 environment of 2. 3 has no hydride and exhibits am ixed-valent [AuCu 11 ] 10+ metal core,m aking it at wo-electron superatom.

Locating Interstitial Hydrides in MH2@Cu14 (M = Cu, Ag) Clusters by Single-Crystal X-ray Diffraction

“…Hence, the presence of the hydride is indisputable. Similarly, the same composition is observed for compound 2 compared to the previously published X-ray (denoted as 2b ) and neutron (denoted as 2b N ) structures . However, the three crystals were crystallized in different space groups ( 2 : C 2/ c , 2b : P 1̅, 2b N : P 2 1 / c ).…”

“…To supplement XRD analysis, computational methods such as Hirshfeld atomic refinement (HAR) have been developed, enabling anisotropic refinements for hydrogen atoms, although the accuracy is somewhat lower compared to atomic displacement parameters (ADPs) obtained from neutron diffraction. , It is important to consider the quality of the diffraction data, as insufficient data may limit the refinement to isotropic parameters. In contrast to theoretical calculations, a machine learning-based approach has also been employed to predict the possibility of hydride positions in copper hydride compounds. , The algorithm utilized in this method is trained with a limited data set of previously solved neutron crystal structures. − One of the key benefits of employing machine learning in this context is its potential to accelerate the analysis process and decrease the reliance on costly and time-consuming experimental techniques. However, it should be emphasized that the accuracy and reliability of these methods are still undergoing assessment.…”

“…In our previous studies, we utilized XRD to ascertain hydride positions within the metal framework, which were subsequently validated with greater precision through neutron diffraction. − For instance, in the case of [Cu 20 H 11 {S 2 P­(O i Pr) 2 } 9 ], an undisclosed near-square planar, four-coordinate hydride was initially revealed by XRD and later confirmed by neutron experiments . It is important to highlight the congruity between the hydride positions determined in both X-ray and neutron structures.…”

“…Hence, gaining insights into the precise positions of hydrides within the metal framework is significant in comprehending the intricate formation mechanisms. Herein, we provide a detailed structural comparison of the metal cages surrounding these hydrides with other MH 2 @Cu 14 frameworks (M = Cu, Ag, Pd , ). This work provides a thoughtful and accurate assessment of the considerations and challenges associated with anisotropic refinement for H atoms, particularly in X-ray data collection.…”

Synthesis, structure anatomy, and catalytic properties of Ag14Cu2 nanoclusters co-protected by alkynyl and phosphine ligands

“…[24][25][26] Specifically, in the catalytic regime, the strong electronic interaction between the alkynyl molecules and the metal can facilitate electron shuttling between the metal cores and the surface capping ligands, resulting in improved catalytic activity. [27][28][29][30][31][32][33][34] For instance, the Wang group documented that, for the semi-hydrogenation of alkynes, alkynyl-protected Au 38 nanoclusters exhibited nearly 100% conversion of a substrate with good product selectivity, but thiolate-protected Au 38 clusters demonstrated a negligible conversion rate. 5 In another study, the Tsukuda group reported a similar ligand effect in the electrochemical hydrogen evolution reaction (HER), where the onset potential of Au 25 (CuCR) 18 was about 70 mV more positive than that of Au 25 (SR) 18 under the same conditions.…”