RESUMEN
The generation and regulation of chirality are closely related to the origin of life. Using achiral precursors to spontaneously build chiral MOFs remains a major challenge. Here, a method to synthesize chiral MOFs from achiral precursors by utilizing chiral fragments was achieved. The transformation from chiral fragments of 1 to chiral frameworks of 2 and 3 was realized by modifying the substituents, and the enantiomer resolution of 3-P41212 and 3-P43212 was achieved by d/l camphoric acid. 3 was then further studied in applications.
Asunto(s)
Estructuras MetalorgánicasRESUMEN
In this work, inspired by a water-assisted three-dimensional supramolecular structure 1, we use a mixed-ligand strategy to form a 3D pillared-layered matrix by the introduction of linear ligands to compete against the water molecules. The resulting analogue microporous MOFs of 2-H, 2-F and 2-N, decorated with different functional groups, similarly show the CO2 uptake. Thanks to the negligible N2 adsorption capacity, enhanced selective adsorption towards CO2 is achieved in compound 2-N. That is, we present here an alternative plan for the high CO2 selective adsorption performance. In addition, the structure stability and moderate affinity for CO2 of these microporous MOFs endow them with excellent reusability.
RESUMEN
The title Cd(II) compound, {[Cd2(C13H7NO4)2(H2O)4]·5H2O}n, was synthesized by the hydrothermal reaction of Cd(NO3)2·4H2O and 5-(pyridin-4-yl)isophthalic acid (H2L). The asymmetric unit contains two crystallographically independent Cd(II) cations, two deprotonated L(2-) ligands, four coordinated water molecules and five isolated water molecules. One of the Cd(II) cations adopts a six-coordinate octahedral coordination geometry involving three O atoms from one bidentate chelating and one monodentate carboxylate group of two different L(2-) ligands, one N atom of another L(2-) ligand and two coordinated water molecules. The second Cd(II) cation adopts a seven-coordinate pentagonal-bipyramidal coordination geometry involving four O atoms from two bidentate chelating carboxylate groups of two different L(2-) ligands, one N atom of another L(2-) ligand and two coordinated water molecules. Each L(2-) ligand bridges three Cd(II) cations and, likewise, each Cd(II) cation connects to three L(2-) ligands, giving rise to a two-dimensional graphite-like 6(3) layer structure. These two-dimensional layers are further linked by O-H···O hydrogen-bonding interactions to form a three-dimensional supramolecular architecture. The photoluminescence properties of the title compound were also investigated.