配体保护的Au_(20+8N)(SR)_(16+4N)团簇的结构、幻数稳定性和电子结构研究
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- 英文论文题名：Structure, Magic Stability and Electronic Structure Properties of Homologous Au_(20+8N)(SR)_(16+4N) Clusters
- 论文作者：裴勇 ; 马忠云 ; 汪璞
- 英文论文作者：Yong Pei ; Zhongyun Ma ; Pu Wang ; Department of Chemistry ; Xiangtan University
- 年：2016
- 作者机构：湘潭大学化学学院;
- 论文关键词：金纳米团簇 ; 密度泛函理论 ; 结构预测 ; 光谱计算
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十分会：纳米体系理论与模拟
- 语种：中文
- 分类号：O641.4
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十分会 ; 纳米体系理论与模拟
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：290k
- 原文格式：D
- 会议级别：全国
摘要
团簇的结构演化规则及其结构-电子结构性质关系是团簇研究领域的一个重要研究方向。通过理论计算研究,本文报道一类新颖具有同源结构的一维巯基(SR)配体保护金纳米团簇(简写做Au_(20+8N)(SR)_(16+4N))的结构、电子性质、光吸收谱及幻数稳定性质。通过这一研究,我们揭示了近期报道的诸多团簇如Au_(28)(SR)_(20),Au_(36)(SR)_(24),Au_(44)(SR)_(28)和Au_(52)(SR)_(32)的结构的内在关联性。在此基础上,我们首先成功地理论预测了近期被实验合成的Au_(76)(SR)_(44)团簇的结构,用该理论预测团簇结构计算得到的紫外-可见光吸收谱图与实验测量数据非常吻合,揭示了配体保护及非球形的团簇结构对金纳米结构光吸收性质的影响,成功地解释了被实验观测到的该团簇的强的可见光区吸收性质。进一步,我们系统地研究了具有不同N的Au_(20+8N)(SR)_(16+4N)团簇的结构和性质。利用骨架电子对理论,很好地解释了此类团簇的较大HOMO-LUMO能系的产生原因;提出了此类团簇的结构演化规则和可能的机制;揭示了已被实验报道的团簇的幻数稳定性根源。
The one-dimensional growth of polytetrahedral ligand protected gold nanoclusters is revealed through structure prediction of Au_(76)(SR)_(44) cluster. We find that the Au_(76)(SR)_(44) cluster contain an anisotropic face-centered cubic(FCC) Au-core. The intense near infrared(NIR) absorption of Au_(76)(SR)_(44) is attributed to synergistic effect of anisotropic cluster structure and ligand protections. The Au_(76)(SR)_(44) and recently reported Au_(52)(SR)_(44), Au_(44)(SR)_(28), Au_(36)(SR)_(44) and Au_(28)(SR)_(20) belong to a family of homologous Au_(20+8N)(SR)_(16+4N) cluster whose Au-cores follow one-dimensional polytetrahedral growth pathway. A plausible cluster-to-cluster growth mechanism is proposed. The odd-N clusters show higher thermodynamics stability than the even N clusters due to the smaller deviations of positions of Au-atoms in comparison to the crystalline structure. Finally, the size-dependent optical absorption properties of ever-elongated Au_(20+8N)(SR)_(16+4N)(N ≥ 8) clusters is revealed.
The one-dimensional growth of polytetrahedral ligand protected gold nanoclusters is revealed through structure prediction of Au_(76)(SR)_(44) cluster. We find that the Au_(76)(SR)_(44) cluster contain an anisotropic face-centered cubic(FCC) Au-core. The intense near infrared(NIR) absorption of Au_(76)(SR)_(44) is attributed to synergistic effect of anisotropic cluster structure and ligand protections. The Au_(76)(SR)_(44) and recently reported Au_(52)(SR)_(44), Au_(44)(SR)_(28), Au_(36)(SR)_(44) and Au_(28)(SR)_(20) belong to a family of homologous Au_(20+8N)(SR)_(16+4N) cluster whose Au-cores follow one-dimensional polytetrahedral growth pathway. A plausible cluster-to-cluster growth mechanism is proposed. The odd-N clusters show higher thermodynamics stability than the even N clusters due to the smaller deviations of positions of Au-atoms in comparison to the crystalline structure. Finally, the size-dependent optical absorption properties of ever-elongated Au_(20+8N)(SR)_(16+4N)(N ≥ 8) clusters is revealed.
引文
[1]Pei,Y.;Lin,S.;Su,J.;Liu,C.J.Am.Chem.Soc.2013,135,19060-19063.
[2]Pei,Y.*;Ma,Z.;Wang,P.;Tang,J.manuscript is under review.
[2]Pei,Y.*;Ma,Z.;Wang,P.;Tang,J.manuscript is under review.