Comparative study of carbon and BN nanographenes: Ground electronic states and energy gap engineering
Comparative study of carbon and BN nanographenes: Ground electronic states and energy gap engineering
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DOI：
10.1021/jp801679j
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发表时间：
2008-07
影响因子：
3.7
通讯作者：
Xingfa Gao;Zhen Zhou;Yuliang Zhao;S. Nagase;Shengbai Zhang;Zhongfang Chen
中科院分区：
文献类型：
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作者：
Xingfa Gao;Zhen Zhou;Yuliang Zhao;S. Nagase;Shengbai Zhang;Zhongfang Chen
在B3LYP/6 - 31G*理论水平上研究了碳和氮化硼（BN）纳米石墨烯（NGs）的稳定性与形状构型之间的关系。矩形碳纳米石墨烯（CNGs）的最高占据分子轨道 - 最低未占据分子轨道（HOMO - LUMO）能隙随着石墨烯尺寸的增加而减小，并且与锯齿形边缘的长度呈直接反比关系。由于双锯齿形边缘边界，具有长锯齿形边缘的CNGs具有开壳层单重态基态；相比之下，BN纳米石墨烯（BNNGs）的HOMO - LUMO能隙对尺寸的依赖性较弱；所有BNNGs都具有闭壳层单重态基态，并且那些具有长锯齿形边缘的能隙略大。具有长锯齿形边缘的CNGs在能量上不如具有长扶手椅形边缘的结构异构体有利，而BNNGs则具有相反的偏好。将长锯齿形边缘转变为扶手椅形的化学修饰可以有效地稳定动力学不稳定的CNGs（具有开壳层单重态基态）并改变……
The relationship between stabilities and shape configurations of carbon and boron nitride (BN) nanographenes (NGs) was studied at the B3LYP/6-31G* level of theory. The HOMO−LUMO energy gaps of rectangular-shaped carbon nanographenes (CNGs) decrease as the graphene sizes increase with a direct inverse dependence on the length of zigzag edge. Due to the double zigzag edge boundaries, the CNGs with long zigzag edges have open-shell singlet ground states; in contrast, the HOMO−LUMO energy gaps of BN nanographenes (BNNGs) have a weak dependence with size; all BNNGs have closed-shell singlet ground states, and those with long zigzag edges have slightly larger energy gaps. CNGs with long zigzag edges are less favorable energetically than their structural isomers with long armchair edges, while the BNNGs have the opposite preference. Chemical modifications that change the long zigzag edge into armchair type can efficiently stabilize the kinetically unstable CNGs (with open-shell singlet ground states) and modify ...