Understanding the interactions between adsorbed gas molecules and pore surface at molecular level is vital to rational design and development of gas-selective nanoporous solids, and critical for many important industrial processes. Much current work in the field focuses on the synthesis of functionalized metal–organic frameworks (MOFs) or coordination polymers (CPs), a new class of crystalline adsorbent materials, and their adsorption properties. While much effort has been made on adsorption-based capture and separation of CO2 from other small gas mixtures, no direct structural evidence of CO2-MOF interactions is reported to date.
In a recent paper, Prof. Jing Li and her collaborators from Stony Brook University (Prof. John Parise) and University of Texas-Dallas (Prof. Yves Chabal) investigate the origin of CO2 adsorption selectivity in a nanoporous coordination framework using a combination of techniques including single-crystal X-ray diffraction, in situ X-ray powder diffraction coupled with differential scanning calorimetry, IR spectroscopy, and theoretical calculations. The study reveals that the adsorbed CO2 stays in a “pocket” between two phenyl rings, interacting with the aromatic electron density.
The article has been published in Angewandte Chemie (International Edition), A. M. Plonka, D. Banerjee, W. R. Woerner, Z. Zhang, N. Nijem, Y. J. Chabal, J. Li, J. B. Parise Angew. Chem. Int. Ed. 2013, 52(6), 1692-1695, DOI: 10.1002/anie.201207808.