Modifying the Atomic and Electronic Structures of Gold Nanocrystals via Changing the Chain Length of n-Alkanethiol Ligands
Modifying the Atomic and Electronic Structures of Gold Nanocrystals via Changing the Chain Length of n-Alkanethiol Ligands
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DOI：
10.1021/jp3096117
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发表时间：
2012-11
影响因子：
3.7
通讯作者：
Yong Jiang;P. Yin;Yuanyuan Li;Zhihu Sun;Qinghua Liu;T. Yao;H. Cheng;F. Hu;Z. Xie;B. He;G. Pan;Shiqiang Wei
中科院分区：
文献类型：
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作者：
Yong Jiang;P. Yin;Yuanyuan Li;Zhihu Sun;Qinghua Liu;T. Yao;H. Cheng;F. Hu;Z. Xie;B. He;G. Pan;Shiqiang Wei
配体保护的纳米材料的界面原子和电子结构是至关重要的因素，但人们对此知之甚少。在这里，我们证明了吸附几何结构以及 Au-S 界面的电子结构可以通过改变正烷硫醇配体的烃“尾”长度来定制。完全正链烷硫醇（n = 3、8 和 12）封端的 3.0 nm Au 纳米晶体在溶液中通过 Au L3 边缘的 X 射线吸收精细结构进行表征。随着烷基长度的增加，头基S原子占据纳米晶表面位点，配位逐渐升高，Au-S键长逐渐缩短。因此，来自最长的正链烷硫醇封端的最强的 Au-S 相互作用导致最显着的 d 电荷从表面 Au 层转移到 S 原子。
The interfacial atomic and electronic structures of ligand-protected nanomaterials are vital factors but are inadequately known. Here, we demonstrate that the adsorption geometry, as well as the electronic structures of Au–S interface, can be tailored via varying the hydrocarbon “tail” lengths of n-alkanethiol ligands. Fully n-alkanethiols (n = 3, 8, and 12) capped Au nanocrystals of 3.0 nm were characterized in solution by X-ray absorption fine structure at the Au L3-edge. With increasing alkyl length, it is found that the headgroup S atom occupies the nanocrystals surface sites with gradually higher coordinations, along with the progressively shortened Au–S bond length. As a result, the strongest Au–S interactions coming from the longest n-alkanethiols capping lead to the most significant d charge transfer from the surface Au layer to the S atoms.