Out-of-Oblivion Cage Molecules and Their Porous Crystalline Phases

An automated molecular porosity detection approach was developed and applied to PubChem, a repository of ca. 94 million molecules, to discover intrinsically porous cage molecules, which, although previously considered by chemists, have remained in oblivion to the porous solids community as neither their crystal structures nor solid-state porosity have been previously reported. The effort led to identification of six such cage molecules reported over the span of the last two decades. The following crystal structure prediction effort suggested that these molecules can form stable low-energy porous crystalline phases. One of the identified lowest energy phases exhibits zeolite-range porosity with pore diameters of ca. 8 Å and internal surface area of 1070 m2/g.本研究开发了一种自动化分子孔隙度检测方法，并将其应用于收录约9400万条分子数据的PubChem数据库，以筛选本征多孔笼状分子。尽管化学家此前曾关注过这类分子，但由于既未报道其晶体结构，也未报道其固态孔隙特征，它们长期被多孔固体研究领域所忽视。本次研究最终筛选出过去二十年间报道过的6种此类笼状分子。后续开展的晶体结构预测研究表明，这类分子可形成稳定的低能多孔晶相。在所筛选出的最低能晶相中，有一种具备沸石级孔隙特性，孔径约为8 Å，比表面积达1070 m²/g。