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Abstract The recovery and separation of organic solvents is highly important for the chemical industry and environmental protection. In this context, porous organic polymers (POPs) have significant potential owing to the possibility of integrating shape‐persistent macrocyclic units with high guest selectivity. Here, we report the synthesis of a macrocyclic porous organic polymer (np‐POP) and the corresponding model compound by reacting the cyclotetrabenzil naphthalene octaketone macrocycle with 1,2,4,5‐tetraaminobenzene and 1,2‐diaminobenzene, respectively, under solvothermal conditions. Co‐crystallization of the macrocycle and the model compound with various solvent molecules revealed their size‐selective inclusion within the macrocycle. Building on this finding, thenp‐POP with a hierarchical pore structure and a surface area of 579 m2 g−1showed solvent uptake strongly correlated with their kinetic diameters. Solvents with kinetic diameters below 0.6 nm – such as acetonitrile and dichloromethane – showed high uptake capacities exceeding 7 mmol g−1. Xylene separation tests revealed a high overall uptake (~34 wt %), witho‐xylene displaying a significantly lower uptake (~10 wt % less than other isomers), demonstrating the possibility of size and shape selective separation of organic solvents.
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Unblocking a rigid purine MOF for kinetic separation of xylenes
The separation of xylene isomers still remains an industrially challenging task. Here, porous purine-based metal–organic frameworks (MOFs) have been synthesized and studied for their potential in xylene separations. In particular, Zn(purine)I showed excellent para -xylene/ ortho -xylene separation capability with a diffusion selectivity of 6 and high equilibrium adsorption selectivity as indicated by coadsorption experiments. This high selectivity is attributed to the shape and size of the channel aperture within the rigid framework of Zn(purine)I.
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- Award ID(s):
- 1834750
- PAR ID:
- 10392727
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 58
- Issue:
- 88
- ISSN:
- 1359-7345
- Page Range / eLocation ID:
- 12305 to 12308
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract The crystal structure of a commercially available anthracene derivative, anthracene‐9‐thiocarboxamide, is reported here for the first time. The compound undergoes a [4+4] cycloaddition in the solid state to afford facile synthesis of the cycloadduct (CA). The cycloaddition is also reversible in the solid state using heat or mechanical force. Due to the presence of unpaired, strong hydrogen‐bond donor atoms on the CA, significant solvatomorphism is achieved, and components of the solvatomorphs self‐assemble into four different classes of supramolecular structures. The CA readily crystallizes with a variety of structurally‐diverse solvents including those containing oxygen‐, nitrogen‐, or pi‐acceptors. Some of the solvents the CA crystallized with include thiophene, benzene, and the three xylene isomers; thus, the CA was employed in industrially‐relevant solvent separation. However, in competition studies, the CA did not exhibit selectivity. Lastly, it is demonstrated that the CA crystallizes with vinyl‐containing monomers and is currently the only compound that crystallizes with both widely used monomers 4‐vinylpyridine and styrene. Solid‐state complexation of the CA with the monomers affords over a 50 °C increase in the monomer's thermal stabilities. The strategy of designing molecules with unused donors can be applied to achieve separations or volatile liquid stabilization.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d2cc04387d
