Doping‐Mediated Energy‐Level Engineering of M@Au₁₂ Superatoms (M=Pd, Pt, Rh, Ir) for Efficient Photoluminescence and Photocatalysis

Abstract

We synthesized a series of MAu12(dppe)5Cl2 (MAu12; M=Au, Pd, Pt, Rh, or Ir; dppe=1,2‐bis(diphenylphosphino)ethane), which have icosahedral M@Au12 superatomic cores, and systematically investigated their electronic structures, photoluminescence (PL) and photocatalytic properties. The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) was expanded when doping an M element positioned at the lower left of the periodic table. The PL quantum yield was enhanced with an increase in the HOMO–LUMO gap and reached 0.46–0.67 for MAu12 (M=Pt, Rh, or Ir) under deaerated conditions. The bright PLs from MAu12 (M=Pt, Rh, or Ir) were assigned to phosphorescence based on quenching by O2. MAu12 (M=Pt, Rh, or Ir) acted as a more efficient and stable photocatalyst than Au13 for intramolecular [2+2] cycloaddition of bisenone via the oxidative quenching cycle. This study provides rational guides for designing photoluminescent and photocatalytic gold superatoms by the doping of heterometal elements.

Near-Infrared Dual Emission from the Au42(SR)32 Nanocluster and Tailoring of Intersystem Crossing

“…Such a model can be extended to assemblies where the split excited states become denser and yield a band-like electronic structure (Scheme B), evidenced by the 806 nm peak broadening in the film’s UV–vis absorption spectrum (Figure S9). According to Fermi’s golden rule, the intersystem crossing rate can be described by eq , k normalI normalS normalC ∝ | ⟨ Ψ S | H normalS − normalO | Ψ T ⟩ | normalΔ E normalS − normalT where Δ E S – T is the energy gap between singlet and triplet states, H S – O is the Hamiltonian describing the spin–orbit coupling, and Ψ S and Ψ T are wave functions for singlet and triplet states, respectively. Without any change in the structure of Au 42 between the solution and solid state, the difference in the perturbation term caused by spin–orbit coupling should be negligible.…”

“…44 Such a model can be extended to assemblies where the split excited states become denser and yield a bandlike electronic structure (Scheme 1B), 45 evidenced by the 806 nm peak broadening in the film's UV−vis absorption spectrum (Figure S9). According to Fermi's golden rule, the intersystem crossing rate can be described by eq 2, 46 (2)…”

Supervalence Bonding in Bi-icosahedral Cores of [M1Au37(SC2H4Ph)24]− (M = Pd and Pt): Fusion-Mediated Synthesis and Anion Photoelectron Spectroscopy

“…The structures look nearly identical to that of Au 23 : they are composed of bi-icosahedral M1Au 22 (M = Pd and Pt) cores protected by three Au 1 (PET) 2 and six Au 2 (PET) 3 oligomers. , The location of the Pd dopant in Pd 1 Au 22 was identified at one of the centers of two icosahedrons, , whereas that of the Pt dopant in Pt 1 Au 22 was not identified because Au and Pt could not be distinguished by SCXRD. Nevertheless, it is most likely that the Pt dopant occupied either the center of the bi-icosahedrons based on the previous examples in which Pt exclusively took the central site of Au superatoms. ,,,,− A qualitative comparison of the geometric structures of M 1 Au 22 (M = Pd, Pt, and Au) is summarized in Table . Although a slight elongation in the interdimer distance D i – i was observed, the bond lengths within Au 23 and M 1 Au 22 (M = Pd and Pt) are comparable.…”

“…Nevertheless, it is most likely that the Pt dopant occupied either the center of the bi-icosahedrons based on the previous examples in which Pt exclusively took the central site of Au superatoms. 24 , 30 , 31 , 34 , 40 − 45 A qualitative comparison of the geometric structures of M 1 Au 22 (M = Pd, Pt, and Au) is summarized in Table 3 . Although a slight elongation in the interdimer distance D i – i was observed, the bond lengths within Au 23 and M 1 Au 22 (M = Pd and Pt) are comparable.…”

Depletion Driven Assembly of Ultrasmall Metal Nanoclusters: From Kinetically Arrested Assemblies to Thermodynamically Stable, Spherical Superclusters

“…Subnanometer sized, metal nanoclusters (MNCs) are unique class of nanoscale material with molecule-like properties such as HOMO–LUMO transitions, photoluminescence (PL), large Stokes shift, chirality, intrinsic magnetism, etc. − These excellent properties endow MNCs suitable for various applications such as sensing, catalysis, bioimaging, therapy, etc. − An effective way to enrich their functional diversity is to build self-assembled superstructures through various interactions. − Particularly, from the supramolecular point of view, MNCs with well-defined size and composition could be an ideal building block as it holds all the essential components for directing the self-assembly process. By means of supramolecular interactions such as H-bonding, hydrophobic interaction, electrostatic interaction, Π–Π stacking, etc., a wide variety of MNC-based self-assembled superstructures could be created across multiple length scales and dimensions. − These superstructures offer large diversity in physicochemical properties and thus broaden their horizon for many practical applications. − …”