Absolute configuration retention of a configurationally labile ligand during dynamic processes of thiolate protected gold clusters
| Autor: | Esko Makkonen, Yanan Wang, Xi Chen, Thomas Bürgi |
|---|---|
| Přispěvatelé: | University of Geneva, Department of Applied Physics, Computational Electronic Structure Theory, Aalto-yliopisto, Aalto University |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
MECHANISM
NANOPARTICLE 02 engineering and technology 010402 general chemistry 01 natural sciences MONOLAYER CIRCULAR-DICHROISM chemistry.chemical_compound AU-38(SR)(24) Cluster (physics) EXCHANGE REACTIONS AU-38 Racemization SPECTROSCOPY Ligand Chiral ligand Absolute configuration Diastereomer Dithiol AU-25 NANOCLUSTERS General Chemistry 021001 nanoscience & nanotechnology REACTIVITY 0104 chemical sciences Chiral column chromatography Chemistry Crystallography chemistry ddc:540 0210 nano-technology |
| Zdroj: | Chemical science, Vol. 12, No 27 (2021) pp. 9413-9419 Chemical Science |
| ISSN: | 2041-6520 |
| Popis: | Monolayer protected metal clusters are dynamic nanoscale objects. For example, the chiral Au38(2-PET)24 cluster (2-PET: 2-phenylethylthiolate) racemizes at moderate temperature. In addition, ligands and metal atoms can easily exchange between clusters. Such processes are important for applications of monolayer protected metal clusters; however, the mechanistic study of such processes turns out to be challenging. Here we use a configurationally labile, axially chiral ligand, biphenyl-2,2′-dithiol (R/S-BiDi), as a probe to study dynamic cluster processes. It is shown that the ligand exchange of free R/S-BiDi on a chiral Au38(2-PET)24 cluster is diastereospecific. Using chiral chromatography, isolated single diastereomers of the type anticlockwise/clockwise-Au38(2-PET)22(R/S-BiDi)1 could be isolated. Upon heating, the cluster framework racemizes, while the R/S-BiDi ligand does not. These findings demonstrate that during cluster racemization and/or ligand exchange between clusters, the R/S-BiDi ligand is sufficiently confined, thus preventing its racemization, and exclude the possibility that the ligand desorbs from the cluster surface. The ligand exchange between a configurationally labile BiDi ligand and intrinsically chiral Au38 gold nanoclusters is diastereoselective. More importantly, the adsorbed ligand retains its configuration during dynamic cluster processes. |
| Databáze: | OpenAIRE |
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