Surfactant-free Synthesis of Ultrasmall Gold Nanoclusters
Surfactant-free Synthesis of Ultrasmall Gold Nanoclusters
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DOI：
10.1021/jp9067944
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发表时间：
2010-01
影响因子：
3.7
通讯作者：
S. M. Reilly;T. Krick;A. Dass
中科院分区：
文献类型：
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作者：
S. M. Reilly;T. Krick;A. Dass
表面活性剂（通常是四辛基溴化铵）在两相Brust金纳米簇合成中的作用（Brust， M.; Walker， M.; Bethell， D.; Schiffrin， D. J.; Whyman， R. J. Chem.）。Soc。,化学。common . 1994, 801)一直不清楚。报道了以NaBH4为还原剂，在过量硫醇：金比（bbb3）和低温反应温度等常规合成条件下，在二氯甲烷中无表面活性剂合成金纳米团簇的结果。以Au(I)SR副产物为原料，获得了产率约5%的纳米团簇混合物。用质谱、紫外可见光谱和核磁共振光谱对分离的金纳米团簇进行了表征。MALDI-TOF质谱分析显示在Au16 - Au31尺寸范围内存在纳米团簇的混合物。紫外可见光谱的离散特征表明存在小于2 nm的小颗粒。相对尖锐的核磁共振峰证实了MALDI-TOF ms所提示的纳米团簇的小尺寸。
The role of surfactant (most often tetraoctylammonium bromide) in the two-phase Brust gold nanocluster synthesis (Brust, M.; Walker, M.; Bethell, D.; Schiffrin, D. J.; Whyman, R. J. Chem. Soc., Chem. Commun. 1994, 801) has been unclear. The results of the surfactant-free synthesis of gold nanoclusters in methylene chloride employing NaBH4 as a reducing agent with the usual synthetic conditions such as excess thiol:gold ratio (>3) and ice-cold reaction temperature are reported. A nanocluster mixture, ∼5% yield with Au(I)SR byproducts, was obtained. The isolated Au nanoclusters were characterized by mass spectrometry, UV−visible, and nuclear magnetic resonance spectroscopy. MALDI-TOF mass spectrometry reveals the presence of mixtures of nanoclusters in the Au16−Au31 size range. Discrete features in the UV−visible spectrum suggested the presence of small <2 nm particles. Relatively sharp peaks in NMR confirm the small size of the nanoclusters as suggested by MALDI-TOF MS. These results are in contrast to the...