Akola Jaakko, Rytkönen Kari, Manninen Matti
Institut für Festkörperforschung, Forschungszentrum Jülich, D-52428 Jülich, Germany.
J Phys Chem B. 2006 Mar 23;110(11):5186-90. doi: 10.1021/jp054896b.
Possible ways for manipulating carbon nanotubes (CNTs) with cyclic supermolecules are studied using density functional theory. Electronic structure calculations with structure optimizations have been performed for the (4,4) and (8,0) single-walled carbon nanotubes (SWNTs) complexed with crown ethers as well as for the (4,0) SWNT with beta-cyclodextrin. A slight polarization of charge in both the nanotube and the supermolecule is observed upon rotaxane complexation, but the interaction is mainly repulsive, and the systems stay 2.8-3.5 A apart. The supermolecule does not affect the electronic band structure of the nanotube significantly within such a configuration. The situation differs noticeably for chemically cross-linked SWNTs and crown ethers, where a peak arises at the Fermi energy in the density of states. As a result, the band gap of semiconducting CNT(8,0) (0.5 eV) vanishes, and a new conduction channel opens for the metallic CNT(4,4).
利用密度泛函理论研究了用环状超分子操纵碳纳米管（CNT）的可能方法。对与冠醚络合的（4,4）和（8,0）单壁碳纳米管（SWNT）以及与β-环糊精络合的（4,0）SWNT进行了结构优化的电子结构计算。在轮烷络合时，在纳米管和超分子中均观察到轻微的电荷极化，但相互作用主要是排斥性的，体系间距保持在2.8 - 3.5 Å。在这种构型下，超分子对纳米管的电子能带结构影响不大。对于化学交联的SWNT和冠醚，情况明显不同，此时态密度在费米能量处出现一个峰值。结果，半导体CNT(8,0)（0.5 eV）的带隙消失，金属CNT(4,4)开启了一个新的传导通道。
