Molecular Dynamics Simulations of Gas Selectivity in Amorphous Porous Molecular Solids
Molecular Dynamics Simulations of Gas Selectivity in Amorphous Porous Molecular Solids
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DOI：
10.1021/ja407374k
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发表时间：
2013-11-27
影响因子：
15
通讯作者：
Cooper, Andrew I.
中科院分区：
文献类型：
--
作者：
Jiang, Shan;Jelfs, Kim E.;Cooper, Andrew I.
一些有机笼状分子的结构具有受保护的内部孔隙体积，无论固态填充模式如何，这些结构都不能填充：即它们本质上是多孔的。对于这些材料，无定形填料可以提供比晶体填料更高的孔体积，但对于无法用X射线衍射表征的无序固体，这种额外孔隙率的确切性质很难理解。在这里，我们描述了一种计算方法，用于生成与实验数据一致的无定形多孔有机笼子的结构模型。分子动力学模拟使观察到的气体在这些无定形固体中的选择性合理化，并导致对自扩散系数、气体扩散轨迹和气体跳跃机制的深入了解。这些方法可能适用于新的无定形多孔固体的从头设计，用于特定应用，其中“刚性主体”近似是不适用的。
Some organic cage molecules have structures with protected, internal pore volume that cannot be in-filled, irrespective of the solid-state packing mode: that is, they are intrinsically porous. Amorphous packings can give higher pore volumes than crystalline packings for these materials, but the precise nature of this additional porosity is hard to understand for disordered solids that cannot be characterized by X-ray diffraction. We describe here a computational methodology for generating structural models of amorphous porous organic cages that are consistent with experimental data. Molecular dynamics simulations rationalize the observed gas selectivity in these amorphous solids and lead to insights regarding self-diffusivities, gas diffusion trajectories, and gas hopping mechanisms. These methods might be suitable for the de novo design of new amorphous porous solids for specific applications, where "rigid host" approximations are not applicable.