巯基保护的中空金纳米球（英文）  

Thiolate-Protected Hollow Gold Nanospheres

作　　者：许文武 高嶷[1] XU Wenwu;GAO Yi(Division of Interracial Water and Key Laboratory of Interracial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China.)

机构地区：[1]中国科学院上海应用物理研究所水科学与技术研究室,微观界面物理与探测重点实验室,上海201800

出　　处：《物理化学学报》2018年第7期770-775,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(11504396,2I773287)资助项目

摘　　要：基于全统一模型和密度泛函理论(DFT)计算,我们提出了具有高对称性和稳定性的巯基保护的中空金纳米球Au_(60)(SR)_(20)的原子结构。Au_(60)(SR)_(20)由一个二十面体Au_(50)富勒烯中空笼子(由20个四面体Au_4融合构成)和10个[-RS-Au-SR-]订书针结构组成,并遵循"分离和保护"规则。DFT计算表明,这种空心Au_(60)(SR)_(20)纳米球具有大的带隙(1.3 eV)以及在笼中心的核独立化学位移(NICS)为负值(-5),表明其高度的化学稳定性。此外,四面体Au4单元中心的NICS值远大于空心笼中心的NICS值,表明Au_(60)(SR)_(20)的总体稳定性可能来自每个四面体Au_4单元的局部稳定性。正的谐波振动频率说明Au_(60)(SR)_(20)纳米球至少是势能表面的局部最小值。另外,我们还通过融合四面体Au_4层设计了双层中空金纳米球,表明调整中空金纳米球壳层厚度是可行的。最后,我们还介绍了更大的中空金纳米球Au_(180)(SR)_(60)的设计。这项工作提供了可控设计中空金纳米球的新策略。We present the atomic structure of thiolate-protected hollow Au nanosphere （HAuNS）, Au60（SR）20, with high symmetry and stability based on the grand unified model （GUM; Nat. Cornmun. 2016, 7, 13574） and density-functional theory （DFT） calculations. Using C2o fullerene （with /h symmetry） as a template, 20 tetrahedral Au4 units were used to replace the C atoms of C2o, and three Au atoms of each Au4 were fused with three neighboring Au4 units by sharing one Au atom to form an icosahedral Aus0fullerene cage as the inner core. Subsequently, the unfused Au atom in each Au4 was bonded with the [-RS-Au-SR-] staple to form the completely hollow Au60（SR）20 nanosphere. Therefore, the Au60（SR）20 is composed of an icosahedral Au5o fullerene hollow cage （constructed by fusing 20 tetrahedral Au4 units） with 10 [-RS-Au SR-] staples, obeying the ＂divide and protect＂ rule. Each Au4 unit has 2e valence electrons, namely, the tetrahedral Au4（2e） elementary block in the grand unified model. The DFT calculations showed that this hollow Au6o（SR）2o nanosphere had a large HOMO-LUMO （HOMO： the highest occupied molecular orbital; LUMO： the lowest unoccupied molecular orbital） gap （1.3 eV） and a negative nucleus-independent chemical shift （NICS） value （-5） at the center of the hollow cage, indicating its high chemical stability. Furthermore, the NlCS values in the center of the tetrahedral Au4 units were much more negative than that in the center of the hollow cage, revealing that the overall stability of Au60（SR）20 likely stemmed from the local stability of each tetrahedral Au4 unit. The harmonic vibrational frequencies were all positive, suggesting that the HAuNS corresponded to the local minimum of the potential energy surface. In addition, the bilayer HAuNS was designed by fusing the tetrahedral Au4 layers, indicating the feasibility of tuning the thickness of the shell of HAuNS. In bilayer HAuNS, each tetrahedral Au4 unit in the first layer shared four Au atoms, while t

关 键 词：巯基保护的中空金纳米球 密度泛函理论 全统一模型 “分离和保护”规则 核独立化学位移 

分 类 号：O641[理学—物理化学]