Atomically Precise Multimetallic Semiconductive Nanoclusters with Optical Limiting Effects

Abstract

For the first time, multinuclear noble-metal clusters have been successfully stabilized by Ti-oxo clusters. Two unprecedented Ag @Ti -oxo nanoclusters with precise atomic structures were prepared and characterized. The octahedral Ag core has strong Ag-Ag bonds (ca. 2.7 Å), and is further stabilized by direct Ag-O-Ti coordination interactions. Moreover, as a result of different acidic/redox conditions in synthesis, the Ag core can adopt diverse geometric configurations inside the Ti -O shell. Correspondingly, structural differences greatly influence their optical limiting effects. The transmittance reduction activity of the clusters towards 532 nm laser shows a nearly linear concentration dependence, and can be optimized up to about 43 %. This work not only opens a new direction for multimetallic semiconductive nanoclusters with interesting optical properties, but also provides molecular models for important noble-metal/TiO heterogeneous materials.

Ag10Ti28‐Oxo Cluster Containing Single‐Atom Silver Sites: Atomic Structure and Synergistic Electronic Properties

“…More importantly, such molecular design could also provide precise models to explore the interactions between the Ti‐O support and noble‐metal sites. Although we have recently encapsulated an Ag 6 cluster within a Ti 16 ‐oxo shell, to the best of our knowledge, the single noble metal atom doping of titanium‐oxo clusters with exposed active sites on the surface has not been realized yet.…”

A Sodalite‐Type Silver Orthophosphate Cluster in a Globular Silver Nanocluster

“…It has the following remarkable features: 1) it possesses a multi‐shell core of Ag 6 @Ag 24 @Ag 60 @Ag 12 (Supporting Information, Scheme S1); 2) the Ag 24 shell is composed of an unprecedented sodalite‐type SOC {(Ag 3 PO 4 ) 8 }, which is reminiscent of molecular analogues of the Ag 3 PO 4 photocatalyst; 3) an octahedral Ag 6 core is embedded in the interior of this SOC cage while square faces of the sodalite‐type cage are capped with S 2− ions, producing a hexa‐capped polyhedral cluster [Ag 6 @{(Ag 3 PO 4 ) 8 }S 6 ] 6− ; 4) the intricate anionic cluster functions as a template to guide the formation of an outer rhombicosidodecahedron Ag 60 shell, which is topologically reminiscent of the truncated icosahedron C 60 . Noting that, as Ag 6 @Ti 16 ‐oxo core–shell NC reported by Zhang et al, was the first example of Ag cluster stabilized in TOC, 1 shows a fascinating feature of a SOC within a Ag NC.…”

Supramolecular Chemistry of Titanium Oxide Clusters

“…Strikingly, following a similar procedure, but with silver acetate, two novel silver‐enclosing TOCs formed, namely, the anionic [Ag 6 Ti 16 (μ 3 ‐O) 18 (μ 2 ‐O) 4 (C 6 H 5 CO 2 ) 26 (CH 3 CN) 2 ] 2− (denoted as α‐Ag 6 Ti 16 ) and neutral Ag 6 Ti 16 (μ 3 ‐O) 16 (μ 2 ‐O) 4 (C 6 H 5 CO 2 ) 24 Ac 4 (CH 3 CN) 2 (denoted as β‐Ag 6 Ti 16 ) clusters, both of which are the first noble‐metal‐doped TOCs (Figure 5). [25] The Ti 16 O 22 and Ti 16 O 20 frameworks can be viewed as a double‐decker of two cricoid Ti 8 O 8 units connected by μ 2 ‐O and bridging carboxylate ligands. Every six Ag + ions form a hexanuclear silver cluster trapped inside the Ti 16 –oxo shell.…”