一种新颖的十八元环超大孔分子筛骨架拓扑结构CJU-18的设计

The Design for a Novel Topological Structure of Sieve CJU-18 with Super-Large 18 Membered Ring Open Pores

提出了一种新颖的十八元环超大孔分子筛的拓扑结构模型——CJU-18,它属钙霞石笼作用于六方晶系的P_(63)/mmc空间群.与VPI-5类似,具有平行于c方向的十八元环直孔道结构,但侧面有十元环孔道,通过计算该结构模型各原子间的键长、键角,认为该结构有可能存在,采用POWD-MODELING程序,计算了它的理论XRD谱图并绘制出其立体拓扑结构。

A novel topological framework structure of the molecular sieve named CJU-18 is obtained theoretically, which has 18 membered ring open pores. The structure is formed by the assemblage of the second building units: cancrinite cage, according to the hexagonal space groups P63/mmc. It has not only the 18-ring pore channel system which parallels to the c-axis as in VPI-5, but also 10-ring pore channel system along both a and b-axis. The results obtained from calculating the bond distances and angles between the atoms show that the structure may probably exist. By using the POWD-MODELING program and the X-ray powder diffraction pattern the topological structure is described.