This presentation has been moved. To view this presentation, please visit http://pubs.acs.org/iapps/liveslides/pages/index.htm?mscNo=jz300960b Fast Synthesis of Thiolated Au25 Nanoclusters via ProtectionDeprotection Method

1. Fast Synthesis of Thiolated Au25 Nanoclusters
via Protection-Deprotection Method
Xun Yuan, Yong Yu, Qiaofeng Yao,
Qingbo Zhang, and Jianping Xie*
Department of Chemical and Biomolecular
Engineering, National University of Singapore,
4 Engineering Drive 4, 117576, Singapore
*Email: chexiej@nus.edu.sg; Tel: +65 6516 1067
J. Phys. Chem. Lett. 2012, 3, 2310 -2314 1

2. Motivations for This Project
• The design of a fast and efficient synthesis of atomically precise
nanoclusters (NCs) is pivotal in realizing their practical
applications in areas such as biomedical and catalysis.
- Currently, there are two main synthetic strategies for the
synthesis of atomically precise Au NCs.
1. Thiolate-protected Au NCs based on the unique thiolate-Au interactions.
2. Template-directed Au NCs based on the steric hindrance provided by the
template molecules.
- A paradigm shift synthetic strategy (protection-deprotection
method) was developed in this study.
1. Inspired from the protection-deprotection strategy in organic synthesis to
achieve chemoselectivity.
2. Integrated two main synthesis strategies into one protocol: unique
thiolate-Au interactions + steric hindrance of the templates.
3. Faster and more efficient.
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3. Protection-Deprotection Method
HAuCl4
Cysteine
Water
(2) Reduction &
(1) Protection Phase transfer
Cys-AuI
Complexes
CTAB Toluene & NaBH4
S
7 min
CTAB-protected Cys-AuI Complexes CTAB-protected Cys-Au25 NCs in Toluene
Cys-AuI Complexes 2 min (3) Deprotection
CTA+
Cys-Au25 NCs in Water
• Protection: a removable CTAB layer was introduced to protect the thiolate-
AuI complexes during the NaBH4 reduction, leading to the direct formation of
thiolated Au25 NCs.
• Deprotection: the CTAB layer was removed by the addition of a hydrophobic
anionic surfactant, shuttling back the NCs to the aqueous phase.
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4. High Purity of Thiolated Au25 NCs
in Our Crude Product
• Cys: cysteine
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5. Extendable to the Synthesis of
Au25 NCs Protected by Other
Thiolate Ligands
• MPA: 3-mercaptopropionic acid
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6. Conclusions
Protection-Deprotection Method
• Integrated the unique thiolate-Au interactions and the
steric hindrance of a removable template (CTAB) into one
synthetic protocol.
• A simple and fast (< 10 min) synthesis method for high
purity thiolated Au25 NCs.
• A paradigm shift synthetic strategy which could be applied
to synthesize other atomically precise metal NCs.
Please visit our website for more information
Jianping Xie Group @ NUS:
http://cheed.nus.edu.sg/~chexiej/index.html
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