Molecular “surgery” on a 23-gold-atom nanoparticle

Abstract

Changes to surface motifs provide precise tailoring of nanoparticle properties.

Atomically Tailored Gold Nanoclusters for Catalytic Application

“…TheA u 28 (CHT) 20 exhibits aA u 20 kernel with face-centred-cubic (fcc) structure,which is exactly the same kernel in Au 28 (TBBT) 20 (Figure 3A-D). TheA u 20 kernel in both NCs is protected by eight bridging thiolates in the same manner.H owever,f urther protection by staple motifs gives rise to differences in surface structures of the quasi-isomers.F or Au 28 (CHT) 20 ,t he Au 20 kernel with eight thiolates are further protected by two monomeric staples and two trimeric staples ( Figure 3E-G). On the other hand, the same Au 20 (SR) 8 unit in Au 28 (CHT) 20 is protected by four dimeric staples,w here each of them is placed on the {111} facets on the fcc Au 20 kernel.…”

“…More importantly,t he structural determination permits analysis of active sites and the catalytic mechanism at the unprecedented atomic level. The highlighted work includes catalysis by spherical and rod-shaped Au 25 (with different ligands), quasi-isomeric Au 28 (SR) 20 with different Rg roups,s tructural isomers of Au 38 (SR) 24 (with identical R) and Au 38 S 2 (SR) 20 with body-centred cubic (bcc) structure,and isostructural [Au 38 L 20 (PPh 3 ) 4 ] 2+ (different L). [1] Theincrease in accessible sizes and structures of NCs Recent advances in the synthetic chemistry of atomically precise metal nanoclusters (NCs) have significantly broadened the accessible sizes and structures.Suchp articles are well defined and have intriguing properties,thus,they are attractive for catalysis.Especially,those NCs with identical size but different core (or surface) structure provide unique opportunities that allowt he specific role of the core and the surface to be mapped out without complication by the sizeeffect.…”

“…However,r ecent efforts on the "tailoring chemistry" of NCs have enabled the partial or entire structure of the NC to be modified while maintaining the size and/or core struc- Au 21 (SR) 15 [18] fcc-Au 12 fcc-Au 13 Au 21 S(SR) 15 [19] fcc-Au 12 Au 21 (SR) 12 (dppm) 2 [20] fcc-Au 15…”

“…Au 38 (SR) 20 (PPh 3 ) 4 [36] fcc-Au 34 Au 38 (CC-Ph) 20 Au 44 (SR) 26 [40] I h -Au 39 Au 52 Au 52 (SR) 32 [37,41] fcc-Au 48 fcc-Au 50 Au 60 Au 60 Se 2 (PPh 3 ) 10 (SePh) 15 [42] -I h -Au 60 Au 60 S 6 (SR) 36 [43] fcc-Au 20 Au 60 S 7 (SR) 36 [44] fcc-Au 17…”

“…[54] Such comparisons reveal the exclusive role of the surface (i.e., staples and carbon tails) without the complication by the kernel geometry as the isomers have the same Au 20 core. Several Au 38 NCs are also discussed in terms of catalysis,with the reported works including the structural isomers of Au 38 -(PET) 24 for nitrophenol reduction, [8] Au 38 S 2 (SR) 20 and Au 38 -(PET) 24 for photocatalytic oxidation, [55] and two isostructural [Au 38 L 20 (PPh 3 ) 4 ] 2+ NCs (L = SR or PA ,p henylacetylide) for semihydrogenation. [36] Theexploration of catalysis by isomeric NCs has demonstrated the strategy to control the catalytic performance without the complication by the size effect.…”