A nitrogen-doped nanotube molecule with atom vacancy defects
A nitrogen-doped nanotube molecule with atom vacancy defects
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DOI：
10.1038/s41467-020-15662-6
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发表时间：
2020-04-14
影响因子：
16.6
通讯作者：
Isobe, Hiroyuki
中科院分区：
文献类型：
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作者：
Ikemoto, Koki;Yang, Seungmin;Isobe, Hiroyuki
氮掺杂碳纳米管在各个领域引起了人们的关注，但缺乏具有离散分子结构的同系物阻碍了对化学认识的深入发展。在本研究中，通过将8个2，4，6-三取代吡啶单元与32个1，3，5-三取代苯单元相结合，合成了周期掺杂多个氮原子的纳米管分子。一种涉及测地线苯类骨架的合成策略具有足够的通用性，可以容忍吡啶单元，而不需要合成迂回。采用非球面多极原子模型的结晶学分析表明，轴向旋转结构是一种次要的无序结构，这也提供了详细的分子和电子结构。纳米管上的氮原子作为化学上不同的位置，覆盖着带负电荷的表面，它们通过降低应该充当电子受体的未占据轨道的能级来增加电子注入的机会。用杂原子取代纳米碳中的碳原子改变了其固有性质，氮掺杂纳米碳在各个领域引起了广泛的关注。在这里，作者合成了一个离散的氮掺杂纳米管分子，并澄清了它的结构，以揭示氮掺杂的独特特征。
Nitrogen-doped carbon nanotubes have attracted attention in various fields, but lack of congeners with discrete molecular structures has hampered developments based on in-depth, chemical understandings. In this study, a nanotube molecule doped periodically with multiple nitrogen atoms has been synthesized by combining eight 2,4,6-trisubstituted pyridine units with thirty-two 1,3,5-trisubstituted benzene units. A synthetic strategy involving geodesic phenine frameworks is sufficiently versatile to tolerate pyridine units without requiring synthetic detours. Crystallographic analyses adopting aspherical multipole atom models reveal the presence of axially rotated structures as a minor disordered structure, which also provides detailed molecular and electronic structures. The nitrogen atoms on the nanotube serve as chemically distinct sites covered with negatively charged surfaces, and they increase the chance of electron injections by lowering the energy levels of the unoccupied orbitals that should serve as electron acceptors. Replacing carbon atoms in nanocarbons with heteroatoms alters their intrinsic properties, and nitrogen-doped nanocarbons attract much attention in various fields. Here, the authors synthesize a discrete nitrogen-doped nanotube molecule and clarify its structure to reveal unique features of nitrogen dopants.