435663CH4笼型结构中甲烷溢出的理论研究

通过旋转和平移两种操作方式改变435663CH4笼型结构中四元环、五元环、六元环的相对位置,对435663CH4笼型结构的破坏过程以及甲烷溢出的可能性进行了密度泛函(DFT)理论研究,并计算了甲烷溢出笼型结构过程中所需的能垒值。结果表明:与改变五元环、六元环相对位置相比,通过改变四元环相对位置来破坏435663CH4笼型结构是最容易的;当四元环背离笼型结构平移0.30 nm时,甲烷可以顺利溢出笼型结构;当四元环背离笼型结构平移0.25 nm时,再通过旋转来改变四元环相对位置,可以有效降低甲烷溢出笼型结构所需的能垒。

A theoretical study of methane escape in a 435663 CH4 cage

Using the density functional theory (DFT) method, face translation and face rotation have been performed to change the relative positions of the three kinds of faces—namely tetragonal faces, pentagonal faces and hexagonal faces—in 435663CH4 in order to explore the possibility of a CH4 molecule escaping from the cage. Meanwhile, the corresponding energy barriers to the escape of a CH4 molecule were calculated during the course of escape. The results show that, compared with a pentagonal face or hexagonal face, a tetragonal face can most easily change its relative position, and when the tetragonal face moves 030nm away from the rest of cage, the CH4 molecule can overflow the cage smoothly. In addition, if a 0.25nm translation is carried out on the tetragonal face first, further rotation can lower the energy barrier to the CH4 escape of the molecule.