Surface-Assisted Alkane Polymerization: Investigation on Structure-Reactivity Relationship.
Surface-Assisted Alkane Polymerization: Investigation on Structure-Reactivity Relationship.
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DOI：
10.1021/jacs.7b09097
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发表时间：
2018-02
影响因子：
15
通讯作者：
K. Sun;Aixi Chen;Meizhuang Liu;Haiming Zhang;Ruomeng Duan;Penghui Ji;Ling Li;Qing Li;
中科院分区：
文献类型：
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作者：
K. Sun;Aixi Chen;Meizhuang Liu;Haiming Zhang;Ruomeng Duan;Penghui Ji;Ling Li;Qing Li;
烷烃的表面辅助聚合是一个引人注目的反应，其中Au（110）的表面重构是至关重要的。在（1×2）-Au（110）表面预覆盖分子后，通过在脂肪链两侧引入支化的亚甲基（18，19-二甲基十六烷），可以完全转变为（1 ×3）-Au（110），或者在低能电子（对于烷属三十二烷，电子束能量为3.5 ~ 33.6 eV）作用下，局部转变为（1× 3）-Au（110）。扫描隧道显微镜研究表明，吸附在（1×3）-Au（110）上的烷烃链比吸附在（1×2）-Au（110）上的烷烃链具有更高的反应活性，为结构-反应性关系提供了有力的实验证据。这种差异可以归因于在（1×3）-Au（110）的凹槽中存在额外的一排金原子，提供了配位数较低的Au原子的活性位。密度泛函理论模拟进一步证实了实验结果。
Surface-assisted polymerization of alkanes is a remarkable reaction for which the surface reconstruction of Au(110) is crucial. The surface of (1×2)-Au(110) precovered with molecules can be completely transformed into (1×3)-Au(110) by introducing branched methylidene groups on both sides of the aliphatic chain (18, 19-dimethylidenehexatriacontane) or locally shifted into (1×3)-Au(110) under exposure to low-energy electrons (beam energy from 3.5 to 33.6 eV, for alkane dotriacontane). Scanning tunneling microscopy investigations demonstrate that alkane chains adsorbed on (1×3)-Au(110) are more reactive than on (1×2)-Au(110), presenting a solid experimental proof for structure-reactivity relationships. This difference can be ascribed to the existence of an extra row of gold atoms in the groove of (1×3)-Au(110), providing active sites of Au atoms with lower coordination number. The experimental results are further confirmed by density functional theory simulations.