Highly Stable sp2 Carbon-Conjugated Porous Organic Cages

The high-yield synthesis of ultrastable porous or-ganic cages (POCs) by facile methods is highly de-sirable but challenging. Inspired by highly stable sp2 carbon-conjugated (C=C) covalent organic frame-works, we used rational design and synthesized the first family of sp2 carbon-linked POCs (sp2c-POCs) with triangular prism shapes by a one-step Knoevenagel reaction that is a high yield [2+3] con-densation reaction. The stability of sp2c-POC was demonstrated under strenuous conditions involving for example concentrated HCl or saturated NaOH solution. sp2c-POC was used as a robust adsorbent for efficient separation of CO2/CH4 or CO2/N2 mixtures. In view of their facile synthesis and unique properties, we expect widespread use of these sp2 C=C linkages in the development of POC materials.