Tetrahedral Geometry Induction of Stable Ag–Ti Nanoclusters by Flexible Trifurcate TiL₃ Metalloligand

Abstract

A series of increasingly large silver nanoclusters with a varied combination of Archimedean and/or Platonic solid arrangements was constructed using a flexible trifurcate TiL3 (L = Salicylic acid or 5-fluorosalicylic acid) metalloligand: Ag4@Ag4@Ti4 (PTC-85), Ag12@Ti4 (PTC-86), Ag4@Ag6@Ag12@Ti4 (PTC-87), Ag6@Ag24@Ag12@Ti4 (PTC-88), and Ag12@Ag24@Ti4 (PTC-89). The silver nanoclusters are each capped by four TiL3 moieties, thereby forming {Ti4} supertetrahedra with average edge lengths ranging from ∼8.12 Å to ∼17.37 Å. Such {Ti4} moieties further induce the tetrahedral geometry of the encapsulated silver nanoclusters. These atomically precise metallic clusters were found to be ultrastable with respect to air for several months, and to water for more than 3 days, due to the stabilizing effects of the TiL3 metalloligand. Moreover, the obtained clusters exhibit nonlinear optical (NLO) effects in optical limiting tests and also temperature-dependent photoluminescent properties. This work provides an interesting metalloligand method not only to induce the spatial growth of metallic clusters to achieve highly symmetric structures, but also to enhance their stability which is crucial for future application.

Stepwise assembly and reversible structural transformation of ligated titanium coated bismuth-oxo cores: shell morphology engineering for enhanced chemical fixation of CO2

“…Recently, we have found that the Ti(SAC) 3 (H 2 SAC = salicylic acid) moieties can act as versatile metalloligands to stabilize Ag clusters. 39 Similarly, these Ti(SAC) 3 species might also be applied to coat multinuclear Bi-oxo cores to form the desired core–shell nanostructures. Following this consideration, herein we successfully prepared the first core–shell Bi–Ti oxo cluster, [Ti 6 Bi 38 O 45 (SAC) 18 (HSAC) 12 ]·2(H 2 O)·4(NBA)·11(DMF) (NBA = 1-butanol) (PTC-281).…”

Small symmetry-breaking triggering large chiroptical responses of Ag70 nanoclusters

“…13 ), the 70-Ag atom NC, denoted Ag 4 @Ag 12 @Ag 12 @Ag 6 @Ag 24 @Ag 12 , features a tetrahedron of four Ag atoms (an idealized Platonic solid), a truncated tetrahedron of twelve Ag atoms (an idealized Archimedean solid), a truncated tetrahedron of 12 Ag atoms (an Archimedean solid), an octahedron of six Ag atoms (an idealized Platonic solid), a truncated octahedron of 24 Ag atoms (an Archimedean solid), and a doubly truncated tetrahedron of twelve Ag atoms, with each of the vertices occupied by a Ag atom. This 70-Ag atom aggregate possesses tetrahedral topology 12 , 21 , 22 , 33 – 35 , which incorporates S 2− -passivated FCC-based Ag 16 inner core (Ag− μ 3 -S bond lengths: 2.469(5)−2.489(6) Å; Supplementary Fig. 8 ).…”

“…Well-defined optically pure high-nuclearity metal clusters remain scarce because of the difficulty in separating and crystallizing enantiomers. Although a few chiral medium-sized nanoclusters have been structurally resolved by single-crystal X-ray diffraction analysis 3 , 21 – 23 , they crystallized in racemates, which have pairs of enantiomers in a unit cell of the crystal. Only one case of enantiomerically pure single crystals of a medium-sized (>50 metal atoms) silver nanocluster, Ag 78 , protected by a chiral diphosphine ligand, has been characterized 16 , yet its deracemization process is unclear, and the CD origins are not well assigned.…”

Protection of Ag Clusters by Metal‐Oxo Modules

“…Recently, TiL 3 metalloligands (L = salicylic acid) possessing octahedra TiO 6 unit were artistically applied to protect the Ag clusters by our group. [31] Similar to the tetrahedra MO 4 2À described above, TiL 3 metalloligands can also site {Ag 3 } vertex units and further induce a series of encapsulated silver nanoclusters possessing pyramid geometry with average edge lengths ranging from ~8.12 Å to ~17.37 Å (Scheme 2). Previously, the synthesized Ag clusters were found to be ultrastable with the protection of TiL 3 metalloligands, respecting to air for several months, and to water for more than 3 days.…”

“…Adapted from Ref. [31] with permission from the American Chemical Society. structure of Ag 27 @{Si 2 W 18 } 3 and two Ag + counter cations can be retained after the cleavage reaction, while the generated protons and electrons will be stored on the POM frameworks and the internal {Ag 27 } kernel, respectively.…”