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本文提出三种包含有五员环的新型(准)笼结构单元 ,并基于这些新型的二级结构单元 ,应用“二级结构 空间群组合法”辅以Σ变换设计了MIR系列属于正交晶系Ibam空间群含有16、20、24、28员环主孔道的大孔径新型沸石骨架拓扑结构。估设了这些新型分子筛结构的晶胞常数以及骨架T位原子及氧原子的坐标参数。然后通过能量最小化 ,确定它们稳定构象的全部晶体结构设计细节以及相应的生成热 ;进而讨论了这些结构的稳定性。通过对比、分析不同结构的生成热 ,得到分子筛骨架结构中插入六棱柱笼会使其生成热降低而使结构更趋稳定的推断。
In this paper, we propose three new types of (quasi) cage structure elements that contain a five-member ring. Based on these new secondary structure elements, the MIR series of orthogonal structures are designed using the “secondary structure space group combination method” Department of Ibam space group with a large pore size of 16,20,24,28 main ring hole zeolite skeleton topology. The unit cell constants of these novel molecular sieve structures as well as the coordinate parameters of the T-atom and the oxygen atom of the framework are estimated. The details of the design of all the crystal structures for their stable conformation and the corresponding heat of formation are then determined by minimizing the energy; and the stability of these structures is discussed. By comparing and analyzing the heat of formation of different structures, it is concluded that the insertion of hexagonal prismatic cage into the molecular sieve framework will reduce the heat generation and make the structure more stable.