Phosphine-Stabilized Hidden Ground States in Gold Clusters Investigated via a Au_n(PH₃)_m Database

Abstract

Nanoclusters are promising materials for catalysis and sensing due to their large surface areas and unique electronic structures which can be tailored through composition, geometry, and chemistry. However, relationships correlating synthesis parameters directly to outcomes are limited. While previous computational studies have mapped the potential energy surface of specific systems of bare nanoclusters by generating and calculating the energies of reasonable structures, it is known that environmental ions and ligands crucially impact the final shape and size. In this work, phosphine-stabilized gold is considered as a test system and DFT calculations are performed for clusters with and without ligands, producing a database containing >10000 structures for Au n (PH3) m (n ≤ 12). We find that the ligation of phosphines affects the thermodynamic stability, bonding, and electronic structure of Au nanoclusters, specifically such that “hidden” ground state cluster geometries are stabilized that are dynamically unstable in the pure gold system. Further, the addition of phosphine introduces steric effects that induce a transition from planar to nonplanar structures at 4–5 Au atoms rather than up to 13–14 Au atoms, as previously predicted for bare clusters. This work highlights the importance of considering the ligand environment in the prediction of nanocluster morphology and functionality, which adds complexity as well as a rich opportunity for tunability.

Highly Controllable Fabrication of Gold Composite Nanostructures by Multiple Electroplating for High‐Performance Electrochemical and Raman Scattering Measurements

“…The gold composite nanostructures synthesized on electrodes have a variety of attractive enhancement functions for electrochemical and bioelectrical devices, optical devices, energy devices, etc. For example, surface modification of microelectrodes with gold nanostructures can effectively enhance catalysis, [ 19 ] drug delivery, [ 20 ] electrochemical sensitivity, [ 21 ] as well as electrical double‐layer (EDL) capacitance [ 22 ] due to enlarge their effective surface areas. The increase of electrode surface area can reduce the EDL impedance at the interface between conductive electrode and its adjacent liquid electrolyte, leading to an enhanced sensitivity of impedance measurement.…”

Recent advances in atomic cluster synthesis: a perspective from chemical elements

“…Analogs with heavier atoms, such as organostibines (SbR 3 ), have recently been reported. 61 In the case of phosphines, clusters with group 11 elements, especially gold [62][63][64][65] (sometimes group 10 elements, such as Ni 3 (PPh) (PPh 2 ) 2 (PPh 3 ) 70 (Fig. 3F).…”

Atomically precise gold nanoclusters for CO oxidation: balancing activity and stability by ligand shedding

“…For fully or partially ligand-protected Au NCs, the p orbitals of ligands and d orbitals show mainly contributions for bonding and antibonding states involving a mixing and complicated p-d orbital hybridization (see details for supplementary figure S2). On the other hand, organic ligands located close together experience strong steric effects, in which they play a crucial role as they strive to maximize the distance between ligands by balancing repulsion forces, thereby creating more corner and edge sites on the surface [26].…”

“…The ligand shell surrounding the metal core has been shown to regulate the size, stability and reactivity of these clusters, making them highly tunable for basic energy catalysis [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. For instance, phosphine-coordinated Au 11 NCs with partial ligand removal exhibit high chemical activity for roomtemperature CO oxidation involving a kinetic barrier of 0.7 eV.…”