Exceptionally Stable Microporous Organic Frameworks with Rigid Building Units for Efficient Small Gas Adsorption and Separation.

Three microporous organic frameworks (hereafter denoted as ) based on a rigid adamantane core have been successfully synthesized via Sonogashira-Hagihara polycondensation coupling in high yields, 83.7-94.6%. The obtained amorphous networks have high Brunauer-Emmett-Teller surface areas (up to 737.3 m g), narrow pore size distribution (0.95-1.06 nm), and superior thermal (the initial decomposition temperature under an N atmosphere can reach 410 °C) and chemical stability (no apparent degradation in common organic solvents or strong acid/base solutions after 7 days). At 273 K and 1.0 bar, these networks present good uptake capacities for small gas molecules (13.9 wt % CO and 1.66 wt % CH) for which the presence of high surface area, predominant microporosity, and narrow pore size distribution are beneficial. In addition, the as-prepared networks possess moderate isosteric heats for CO ( = 19.5-30.3 kJ mol) and show desired CO/N and CO/CH selectivity (36.3-38.4 and 4.1-4.3 based on Henry's law and 17.88-24.92 and 4.24-5.70 based on ideal adsorbed solution theory, respectively). With the demonstrated properties, the synthesized networks display potential for small gas storage and separation that can be used in harsh environments because of their superior physical and chemical stability.