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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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Cyclotetrabenzil-Based Porous Organic Polymers with High Carbon Dioxide Affinity
Porous organic polymers (POPs) incorporating macrocyclic units have been investigated in recent years in an effort to transfer macrocycles' intrinsic host–guest properties onto the porous networks to achieve complex separations. In this regard, highly interesting building blocks are presented by the family of cyclotetrabenzoin macrocycles with rigid, well-defined, electron-deficient cavities. This macrocycle shows high affinity towards linear guest molecules such as carbon dioxide, thus offering an ideal building block for the synthesis of CO2-philic POPs. Herein, we report the synthesis of a POP through the condensation reaction between cyclotetrabenzil and 1,2,4,5-tetraaminobenzene under ionothermal conditions using the eutectic zinc chloride/sodium chloride/potassium chloride salt mixture at 250 °C. Notably, following the condensation reaction, the macrocycle favors three-dimensional (3D) growth rather than a two-dimensional one while retaining the cavity. The resulting polymer, named 3D-mPOP, showed a highly microporous structure with a BET surface area of 1142 m2 g−1 and a high carbon dioxide affinity with a binding enthalpy of 39 kJ mol−1. Moreover, 3D-mPOP showed very high selectivity for carbon dioxide in carbon dioxide/methane and carbon dioxide/nitrogen mixtures.
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- Award ID(s):
- 1904998
- PAR ID:
- 10287096
- Date Published:
- Journal Name:
- Organic Materials
- Volume:
- 03
- Issue:
- 02
- ISSN:
- 2625-1825
- Page Range / eLocation ID:
- 346 to 352
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1055/a-1512-5753
