| Autor: |
Martell JD; Department of Chemistry, University of California , Berkeley, California 94720, United States.; Miller Institute for Basic Research in Science, University of California , Berkeley, California 94720, United States., Zasada LB; Department of Chemistry, University of California , Berkeley, California 94720, United States., Forse AC; Department of Chemistry, University of California , Berkeley, California 94720, United States.; Department of Chemical and Biomolecular Engineering, University of California , Berkeley, California 94720, United States.; Berkeley Energy and Climate Institute, University of California , Berkeley, California 94720, United States., Siegelman RL; Department of Chemistry, University of California , Berkeley, California 94720, United States., Gonzalez MI; Department of Chemistry, University of California , Berkeley, California 94720, United States., Oktawiec J; Department of Chemistry, University of California , Berkeley, California 94720, United States., Runčevski T; Department of Chemistry, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Xu J; Jasco Corporation , 2967-5 Ishikawa-machi, Hachioji-shi, Tokyo 192-8537, Japan., Srebro-Hooper M; Faculty of Chemistry, Jagiellonian University , 30-387 Krakow, Poland., Milner PJ; Department of Chemistry, University of California , Berkeley, California 94720, United States., Colwell KA; Department of Chemical and Biomolecular Engineering, University of California , Berkeley, California 94720, United States., Autschbach J; Department of Chemistry, University at Buffalo, State University of New York , Buffalo, New York 14260, United States., Reimer JA; Department of Chemical and Biomolecular Engineering, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States., Long JR; Department of Chemistry, University of California , Berkeley, California 94720, United States.; Department of Chemical and Biomolecular Engineering, University of California , Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States. |
| Abstrakt: |
Chiral metal-organic frameworks have attracted interest for enantioselective separations and catalysis because of their high crystallinity and pores with tunable shapes, sizes, and chemical environments. Chiral frameworks of the type M 2 (dobpdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobpdc 4- = 4,4'-dioxidobiphenyl-3,3'-dicarboxylate) seem particularly promising for potential applications because of their excellent stability, high internal surface areas, and strongly polarizing open metal coordination sites within the channels, but to date these materials have been isolated only in racemic form. Here, we demonstrate that when appended with the chiral diamine trans-1,2-diaminocyclohexane (dach), Mg 2 (dobpdc) adsorbs carbon dioxide cooperatively to form ammonium carbamate chains, and the thermodynamics of CO 2 capture are strongly influenced by enantioselective interactions within the chiral pores of the framework. We further show that it is possible to access both enantiomers of Mg 2 (dobpdc) with high enantiopurity (≥90%) via framework synthesis in the presence of varying quantities of d-panthenol, an inexpensive chiral induction agent. Investigation of dach-M 2 (dobpdc) samples following CO 2 adsorption-using single-crystal and powder X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and density functional theory calculations-revealed that the ammonium carbamate chains interact extensively with each other and with the chiral M 2 (dobpdc) pore walls. Subtle differences in the non-covalent interactions accessible in each diastereomeric phase dramatically impact the thermodynamics of CO 2 adsorption. |
