Lanthanides (Ln) are a group of important elements usually found in nature as mixtures. Their separation is essential for technological applications but is made challenging by their subtly different properties. Here we report that crystallization of homochiral camphorate metal-organic frameworks (MOFs) is highly sensitive to ionic radii of lanthanides and can be used to selectively crystallize a lanthanide element into predesigned MOFs. Two series of camphorate MOFs were synthesized with acetate (Type 1 with early lanthanides La-Dy) or formate (Type 2 with late lanthanides Tb-Lu and Y) as the auxiliary ligand, respectively. The Ln coordination environment in each type exhibits selectivity for Ln(3+) of different sizes, which could form the basis for a new cost-effective method for Ln separation.
We report an ew magnesium metal-organic framework (MOF) (CPM-107) with as pecial interaction with CO 2 . CPM-107 contains Mg 2 -acetate chains crosslinked into a3 D net by terephthalate.I th as an anionic framework encapsulating ordered extra-framework cations and solvent molecules. The desolvated form is closed and unresponsive to common gasses,s uch as N 2 ,H 2 ,a nd CH 4 .Y et, with CO 2 at 195 K, it abruptly opens and turns into ar igid porous form that is irreversible via desorption. Once opened by CO 2 ,C PM-107 remains in the stable porous state accessible to additional gas types over multiple cycles or CO 2 itself at different temperatures.T he porous phase can be re-locked to return to the initial closed phase via re-solvation and desolvation. Such peculiar properties of CPM-107 are apparently linked to aconvergence of factors related to both framework and extraframework features.T he unusual CO 2 effect is currently the only available path to porous CPM-107 which shows efficient C 2 H 2 /CO 2 separation. Scheme 1. Flexible-to-rigid transformation in shape-memory metalorganic frameworks with gate opening.
We report an ew magnesium metal-organic framework (MOF) (CPM-107) with as pecial interaction with CO 2 . CPM-107 contains Mg 2 -acetate chains crosslinked into a3 D net by terephthalate.I th as an anionic framework encapsulating ordered extra-framework cations and solvent molecules. The desolvated form is closed and unresponsive to common gasses,s uch as N 2 ,H 2 ,a nd CH 4 .Y et, with CO 2 at 195 K, it abruptly opens and turns into ar igid porous form that is irreversible via desorption. Once opened by CO 2 ,C PM-107 remains in the stable porous state accessible to additional gas types over multiple cycles or CO 2 itself at different temperatures.T he porous phase can be re-locked to return to the initial closed phase via re-solvation and desolvation. Such peculiar properties of CPM-107 are apparently linked to aconvergence of factors related to both framework and extraframework features.T he unusual CO 2 effect is currently the only available path to porous CPM-107 which shows efficient C 2 H 2 /CO 2 separation.
Metal-organicframeworks(MOFs)orporouscoordinationScheme 1. Flexible-to-rigid transformation in shape-memory metalorganic frameworks with gate opening.
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