4 research outputs found
Directing Intrinsic Chirality in Gold Nanoclusters: Preferential Formation of Stable Enantiopure Clusters in High Yield and Experimentally Unveiling the âSuperâ Chirality of Au
Chiral gold nanoclusters offer significant potential for exploring chirality at a fundamental level and for exploiting their applications in sensing and catalysis. However, their widespread use is impeded by low yields in synthesis, tedious separation procedures of their enantiomeric forms, and limited thermal stability. In this study, we investigated the direct synthesis of enantiopure chiral nanoclusters using the chiral ligand 2-MeBuSH in the fabrication of Au, Au, and Au nanoclusters. Notably, this approach leads to the unexpected formation of intrinsically chiral clusters with high yields for chiral Au and Au nanoclusters. Experimental evaluation of chiral activity by circular dichroism (CD) spectroscopy corroborates previous theoretical calculations, highlighting the stronger CD signal exhibited by Au compared to Au or Au. Furthermore, the formation of a single enantiomeric form is experimentally confirmed by comparing it with intrinsically chiral Au(2-PET) (2-PET: 2-phenylethanethiol) and is supported theoretically for both Au and Au. Moreover, the prepared chiral clusters show stability against diastereoisomerization, up to temperatures of 80°C. Thus, our findings not only demonstrate the selective preparation of enantiopure, intrinsically chiral, and highly stable thiolate-protected Au nanoclusters through careful ligand design but also support the predicted âsuperâ chirality in the Au cluster, encompassing hierarchical chirality in ligands, staple configuration, and core structure
Dynamic behaviour of platinum and copper dopants in gold nanoclusters supported on ceria catalysts
Abstract Understanding the behaviour of active catalyst sites at the atomic level is crucial for optimizing catalytic performance. Here, the evolution of Pt and Cu dopants in Au25 clusters on CeO2 supports is investigated in the water-gas shift (WGS) reaction, using operando XAFS and DRIFTS. Different behaviour is observed for the Cu and Pt dopants during the pretreatment and reaction. The Cu migrates and builds clusters on the support, whereas the Pt creates single-atom active sites on the surface of the cluster, leading to better performance. Doping with both metals induces strong interactions and pretreatment and reaction conditions lead to the growth of the Au clusters, thereby affecting their catalytic behaviour. This highlights importance of understanding the behaviour of atoms at different stages of catalyst evolution. These insights into the atomic dynamics at the different stages are crucial for the precise optimisation of catalysts, which ultimately enables improved catalytic performance
Directing Intrinsic Chirality in Gold Nanoclusters : Preferential Formation of Stable Enantiopure Clusters in High Yield and Experimentally Unveiling the âSuperâ Chirality of Au144
Chiral gold nanoclusters offer significant potential for exploring chirality at a fundamental level and for exploiting their applications in sensing and catalysis. However, their widespread use is impeded by low yields in synthesis, tedious separation procedures of their enantiomeric forms, and limited thermal stability. In this study, we investigated the direct synthesis of enantiopure chiral nanoclusters using the chiral ligand 2-MeBuSH in the fabrication of Au25, Au38, and Au144 nanoclusters. Notably, this approach leads to the unexpected formation of intrinsically chiral clusters with high yields for chiral Au38 and Au144 nanoclusters. Experimental evaluation of chiral activity by circular dichroism (CD) spectroscopy corroborates previous theoretical calculations, highlighting the stronger CD signal exhibited by Au144 compared to Au38 or Au25. Furthermore, the formation of a single enantiomeric form is experimentally confirmed by comparing it with intrinsically chiral Au38(2-PET)24 (2-PET: 2-phenylethanethiol) and is supported theoretically for both Au38 and Au144. Moreover, the prepared chiral clusters show stability against diastereoisomerization, up to temperatures of 80 °C. Thus, our findings not only demonstrate the selective preparation of enantiopure, intrinsically chiral, and highly stable thiolate-protected Au nanoclusters through careful ligand design but also support the predicted âsuperâ chirality in the Au144 cluster, encompassing hierarchical chirality in ligands, staple configuration, and core structure.peerReviewe
Directing Intrinsic Chirality in Gold Nanoclusters: Preferential Formation of Stable Enantiopure Clusters in High Yield and Experimentally Unveiling the âSuperâ Chirality of Au<sub>144</sub>
Chiral gold nanoclusters offer significant potential
for exploring
chirality at a fundamental level and for exploiting their applications
in sensing and catalysis. However, their widespread use is impeded
by low yields in synthesis, tedious separation procedures of their
enantiomeric forms, and limited thermal stability. In this study,
we investigated the direct synthesis of enantiopure chiral nanoclusters
using the chiral ligand 2-MeBuSH in the fabrication of Au25, Au38, and Au144 nanoclusters. Notably, this
approach leads to the unexpected formation of intrinsically chiral
clusters with high yields for chiral Au38 and Au144 nanoclusters. Experimental evaluation of chiral activity by circular
dichroism (CD) spectroscopy corroborates previous theoretical calculations,
highlighting the stronger CD signal exhibited by Au144 compared
to Au38 or Au25. Furthermore, the formation
of a single enantiomeric form is experimentally confirmed by comparing
it with intrinsically chiral Au38(2-PET)24 (2-PET:
2-phenylethanethiol) and is supported theoretically for both Au38 and Au144. Moreover, the prepared chiral clusters
show stability against diastereoisomerization, up to temperatures
of 80 °C. Thus, our findings not only demonstrate the selective
preparation of enantiopure, intrinsically chiral, and highly stable
thiolate-protected Au nanoclusters through careful ligand design but
also support the predicted âsuperâ chirality in the
Au144 cluster, encompassing hierarchical chirality in ligands,
staple configuration, and core structure