Cu²⁺‐Induced Structural Isomers: Effect of Foreign Metal Ions on the Structure and Properties of Silver Nanoclusters

Abstract

Metal ions have an important impact on the precise control of the synthesis and atomic structural arrangement of noble metal nanoclusters. In this work, the effect of metal ions on the isomer generation of metal nanoclusters is revealed for the first time. Compared with the previous Ag23 nanoclusters with two face‐centered cubic (fcc) unit cells twisting 27°, the Ag23 isomer had a higher symmetry structure with two fcc unit cells almost overlapping. In addition, the UV/Vis absorption spectrum of the isomer showed a slight redshift of approximately 14 nm. The redshift might be because of the modulation of electronic structure, which is derived from fine‐tuned crystal structure. Based on the experimental results, we provide mechanisms to explain the Cu2+ effect on the structural isomer. This work reports a significant finding to tune precisely the crystal structure and understand the mechanism of shape‐controlled synthesis of metal nanoclusters.

Chemical Flexibility of Atomically Precise Metal Clusters

“…In addition, Huang et al reported the structural isomer of 5e [Ag 23 (PET) 18 (PPh 3 ) 8 ] NC and revealed the influence of Cu 2+ ion on the structural isomer of Ag 23 NC through the oxidation–decomposition–recombination (ODR) process (Figure ). Compared to the reported Ag 23 NC ( Ag 23 -1 , from Jin’s group) with the two fcc unit cells twisting 27°, the Ag 23 -2 isomer had a higher-symmetry crystal structure with the two fcc unit cells nearly overlapping and was accompanied by significant changes in electronic structure …”

“…Compared to the reported Ag 23 NC 305 (Ag 23 -1, from Jin's group) with the two fcc unit cells twisting 27°, the Ag 23 -2 isomer had a higher-symmetry crystal structure with the two fcc unit cells nearly overlapping and was accompanied by significant changes in electronic structure. 213 4.3.2. Transformation with Different Sizes.…”

“…Additionally, distinct metal precursors have the potential to affect the coordination environment and introduce new ligands. − For hetero-metal doping in metal clusters, a few excellent review articles referenced. − ,, This aspect will be touched upon less extensively in the present Review. Exotic non-metal ions − may alter the charge number, while redox reactions − can induce variations in valence numbers, thereby altering electronic configurations. This, in turn, can lead to transformations in the overall structure and activity.…”

“…Another four Ag 14 fcc cubes or one more squarelike 2 2 are further aggregated to produce a cubic-structured [Ag 63 (SPhF 2 ) 36 (P n Bu 3 ) 8 ] + (2 3 ). The missing, linearly assembled [Ag 23 (PET) 18 (PPh 3 ) 8 ] (2 1 ) via fusion of two fcc cubes into a super-rod was later discovered by Jin and Huang’s group. , Interestingly, the surface ligands have common binding features in the above 4 sizes of the series, i.e., the thiolate ligands cover the faces and edges of the cube (or half cube) while the phosphine ligands are terminated on the eight corners of the cube (or half-cube).…”

“…However, due to the distinctly physical-chemical properties (e.g., the steric hindrance, ,,,, electron-withdrawing/donating, and hydrophobicity and hydrophilicity , ) of different groups of inducers, the original structures may not be the most stable state, and then the structural transformation takes place. (iii) The redox process of clusters is accompanied by reduction and increase of NC electrons, which can cause significant changes in the cluster geometry, in particular, the change of the electronic structure of superatom NCs will induce the structural transformation to a more stable configuration (refs , , , − , and − ). (iv) The inducer does not directly react with the cluster, only changes the physical-chemical environment of the cluster, such as solvent polarity, pH, temperature, light, electric field, and external pressure. ,,,− …”