Motif-to-Core Nucleation in a Decahedral Evolution Pattern

Abstract

The atomic precision of ultrasmall metal nanoclusters has opened the door to elucidating the structural evolution principles of metal nanomaterials at the molecular level. Here, we report a novel set of super-atomic Ag clusters, including [Ag19(TBBT)16(DPPP)4]+ (Ag19), [Ag22(DMAT)8(DPPM)4Cl8]2+ (Ag22), Ag26(SPh3,5‑CF3)15(DPPF)4Cl5 (Ag26), and [Ag30(DMAT)12(DPPP)4Cl8]2+ (Ag30). The core structures of these clusters correspond to one decahedral Ag7, perpendicular bi-decahedrons, three-dimensional penta-decahedrons, and hexa-decahedrons, respectively. The Ag atoms in AgS2 blocks show a strong correlation with the decahedral cores: the five equatorial Ag atoms in the decahedral Ag7 core of Ag19 all adopt the AgS2 coordination, while the Ag atoms in AgS2 blocks of Ag22, Ag26, and Ag30 unexceptionally constitute additional decahedral structures with the core Ag atoms. Specifically, two and four core Ag atoms of Ag26 and Ag30 clusters occupy positions that highly resemble that of Ag (in AgS2 motifs) of Ag22. The strong structural correlation demonstrates the motif-to-core evolution of the surface Ag (on AgS2) to build extra-decahedral blocks. Density functional theory calculations indicate that the 2e, 4e, 6e, and 8e clusters (from Ag19 to Ag30) adopt 1S2, 1S21P2, 1S21P4, and 1S21P6 electron configurations, all of which feature excellent super-atomic characters.

Recent advances in synthesis and properties of silver nanoclusters

“…By employing various combinations of thiol and diphosphine, a rare collection of super-atomic Ag NCs with sizes Ag 19 , Ag 22 , Ag 26 , and Ag 30 , possessing 2, 4, 6, and 8 free valence electrons respectively, has been reported. 37 Interestingly, the cores of these clusters consist of one decahedral Ag 7 , perpendicular bidecahedra, three-dimensional penta-decahedra, and hexadecahedra, respectively. The strong structural correlation demonstrates the motif-to-core evolution of the surface Ag (on AgS 2 ) to construct additional decahedral blocks, offering opportunities to investigate the impact of decahedral evolution patterns on the properties of NCs.…”

[Au9Ag6(CCR)10(DPPM)2Cl2](PPh4): a four-electron cluster with a bi-decahedral twisted metal core

“…7–21 It has been observed that the metal core of many of these clusters shares the same polyhedral units, despite variations in peripheral ligands or metal–ligand motif structures. These polyhedral units encompass an M 13 centered icosahedron, 22–28 an M 6 octahedron, 29–35 an M 13 cuboctahedron 36 and an M 7 decahedron, 37–42 among others, where ‘M’ represents Au, Ag, Cu, or other metal atoms or their mixtures. These fundamental polyhedral units can also be assembled through the sharing of vertices, edges, or faces, expanding the range of structural types for clusters.…”

Influence of the substituents of the thiol ligand on the optical properties of AuCu14

“…However, the systematic research of the substituent influence on the optical properties and excited state dynamics is still lacking, which is important for constructing emission-specific metal nanoclusters. 11,16,17…”