A homoleptic alkynyl-protected [Ag₉Cu₆(^tBuCC)₁₂]⁺ superatom with free electrons: synthesis, structure analysis, and different properties compared with the Au₇Ag₈ cluster in the M₁₅⁺ series

Abstract

We report the first homoleptic alkynyl-protected AgCu superatomic nanocluster of [Ag9Cu6(tBuC≡C)12]+ (NC 1, also Ag9Cu6 in short), which holds a body-centered-cubic structure with the Ag1@Ag8@Cu6 metal core. Such configuration is...

Electrochemical CO2 reduction catalyzed by atomically precise alkynyl-protected Au7Ag8, Ag9Cu6, and Au2Ag8Cu5 nanoclusters: probing the effect of multi-metal core on selectivity

“…Recently, our group reported the quite small all-alkynyl-protected [Ag 15 (C^C-t Bu) 12 ] + NC, which was able to convert CO 2 into CO with a FE CO of $95% at À0.6 V. 33 Also, the rst case on homoleptic alkynyl-protected AgCu superatom of [Ag 9 Cu 6 (C^C-t Bu) 12 ] + was prepared to compare the physicochemical properties with [Au 7 Ag 8 (-C^C-t Bu) 12 ] + , and the two M 15 clusters exhibited distinctly different optical properties due to the metal core difference. 34 The following questions arise immediately: will these two clusters have different CO 2 RR performance as well? Furthermore, as both clusters are belonging to the M 15 series, if the metal core is atomically tailored, how does the CO 2 RR performance change?…”

“…As illustrated in the space-lling structure, one Au site, ve Cu sites, and eight Ag sites on the surface of Au 2 Ag 8 Cu 5 are exposed partially, which might result in the differences in catalytic performance compared with the other M 15 NCs (Ag 9 Cu 6 and Au 7 Ag 8 ). As a note, all the currently reported alkynyl-protected M 15 NCs such as Ag 9 Cu 6 , Au 7 Ag 8 , and Ag 15 have only one type of t Bu-C^C-M-C^C-t Bu (M ¼ Cu/Au/Ag) linear motif 33,34. However, for Au 2 Ag 8 Cu 5 , there are ve types of t Bu-C^C-M-C^C-t Bu (M ¼ Cu/Ag) motifs on the surface, in which the coordination mode of t Bu-C^C-ligands are m 2 -h 1 (Ag/Cu), h 1 (Ag1/Ag2) for motif 1; m 2 -h 1 (Au/Ag/Cu), h 1 (Ag3) for motif 2; m 2 -h 1 (Au/Ag/Cu), h 1 (Ag4) for motif 3; m 2 -h 1 (Au/Ag/Cu), h 1 (Cu1) for motif 4 and m 2 -h 1 (Au/Ag), h 1 (Cu2) for motif 5, respectively (Fig.3b).…”

A Homoleptic Alkynyl‐Protected Au(I)9‐Ag(I)9 Cluster: Structure Analysis, Optical Properties, and Catalytic Implications

“…[13] Therefore, alkynyl-protected metal nanoclusters have demonstrated exceptional catalytic performance in a variety of reactions. [14,15] For instance, Wang's group reported that, when employing two Au 38 nanoclusters of [Au 38 (L) 20 (Ph 3 P) 4 ] 2 + (L = thiolate or alkynyl ligand) to catalyze the semi-hydrogenation of alkynes, the thiolated Au 38 exhibited a rather low conversion (< 2 %), but in stark contrast, the alkynylprotected one is very active (> 97 %). [16] In another report, Tsukuda and co-workers described that, compared to the Au 25 (SC 2 H 4 Ph) 18 molecule, Au 25 (C�CÀ R) 18 (R = 3, 5bis(trifluoromethyl)-phenyl) showed more favorable HER performance, mainly due to that, the alkynyl ligands can significantly affect the electronic structure of Au 13 core, thus accelerating the key protonation step for generating H 2 .…”

“…[19] Recently, our group successfully synthesized the first homoleptic alkynyl-protected AgÀ Cu superatomic nanocluster of [Ag 9 Cu 6 ( t BuC�C) 12 ] + , which has two free electrons. [20] It is worth noting that, according to the superatom theory, the above bimetallic clusters can be defined as superatom with free electrons. [21] Besides to the bimetallic superatomic clusters, there is another type of bimetallic clusters with all the metals are present with + 1 charge and without free electrons in the cluster.…”

“…successfully synthesized two homoleptic alkynyl‐protected [MAu 24 (C≡C−R) 18 ] 2− (M=Pd or Pt; R=3, 5‐bis(trifluoromethyl)‐phenyl) clusters with 8 free electrons, a typical closed electronic structure with robust stability [19] . Recently, our group successfully synthesized the first homoleptic alkynyl‐protected Ag−Cu superatomic nanocluster of [Ag 9 Cu 6 ( t BuC≡C) 12 ] + , which has two free electrons [20] …”