Porous organic cages (POCs) are individual soluble, porous molecules. When fabricated into mixed‐matrix membranes (MMMs), the soluble POC molecules have the potential to exhibit intimate molecular‐level mixing with the polymer matrix. POCs have only recently been incorporated into mixed matrix membrane materials, but this process has not yet resulted in significant improvements of membrane performance. Now, vertex‐functionalized amorphous scrambled porous organic cages (ASPOCs) have been utilized as membrane performance enhancers and the amorphous ASPOC mixtures are observed to distribute throughout the matrix without any indication of particle formation or agglomeration, creating unique, molecularly mixed composite membranes. Overall, the molecularly mixed composite membrane provide significant increases in both membrane permeability and selectivity, offering new avenues for creation of membranes with unique properties in industrially relevant separations.
- Award ID(s):
- 1834750
- NSF-PAR ID:
- 10316195
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 57
- Issue:
- 59
- ISSN:
- 1359-7345
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract -
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Abstract Porous organic cages (POCs) are individual soluble, porous molecules. When fabricated into mixed‐matrix membranes (MMMs), the soluble POC molecules have the potential to exhibit intimate molecular‐level mixing with the polymer matrix. POCs have only recently been incorporated into mixed matrix membrane materials, but this process has not yet resulted in significant improvements of membrane performance. Now, vertex‐functionalized amorphous scrambled porous organic cages (ASPOCs) have been utilized as membrane performance enhancers and the amorphous ASPOC mixtures are observed to distribute throughout the matrix without any indication of particle formation or agglomeration, creating unique, molecularly mixed composite membranes. Overall, the molecularly mixed composite membrane provide significant increases in both membrane permeability and selectivity, offering new avenues for creation of membranes with unique properties in industrially relevant separations.
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Abstract The preparation of a new class of reactive porous solids, prepared via straightforward salt metathesis reactions, is described here. Reaction of the dimethylammonium salt of a magnesium‐based porous coordination cage with the chloride salt of [CrIICl(Me4cyclam)]+affords a porous solid with concomitant removal of dimethylammonium chloride. The salt consists of the ions combined in the expected ratio based on their charge as confirmed by UV–vis and X‐ray photoelectron spectroscopies, ion chromatography (IC), and inductively coupled plasma mass spectrometry (ICP‐MS). The porous salt boasts a Brunauer‐Emmett‐Teller (BET) surface area of 213 m2 g−1. Single crystal X‐ray diffraction reveals the chromium(II) cations in the structure reside in the interstitial space between porous cages. Importantly, the chromium(II) centers, previously shown to react with O2to afford reactive chromium(III)‐superoxide adducts, are still accessible in the solid state as confirmed by UV–vis spectroscopy. The site‐isolated reactive centers have competence toward hydrogen atom abstraction chemistry and display significantly increased stability and reactivity as compared to dissolved ions.
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D1CC02806E
