Controlling the Crystallisation and Hydration State of Crystalline Porous Organic Salts

O'Shaughnessy, Megan, Padgham, Alex ORCID: 0000-0003-1224-6916, Clowes, Rob, Little, Marc, Brand, Michael ORCID: 0000-0002-4556-5609, Qu, Hang, Slater, Anna ORCID: 0000-0002-1435-4331 and Cooper, Andrew
(2023) Controlling the Crystallisation and Hydration State of Crystalline Porous Organic Salts. CHEMISTRY-A EUROPEAN JOURNAL, 29 (64). e202302420-.

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Crystalline porous organic salts (CPOS) are a subclass of molecular crystals. The low solubility of CPOS and their building blocks limits the choice of crystallisation solvents to water or polar alcohols, hindering the isolation, scale-up, and scope of the porous material. In this work, high throughput screening was used to expand the solvent scope, resulting in the identification of a new porous salt, CPOS-7, formed from tetrakis(4-sulfophenyl)methane (TSPM) and tetrakis(4-aminophenyl)methane (TAPM). CPOS-7 does not form with standard solvents for CPOS, rather a hydrated phase (Hydrate2920) previously reported is isolated. Initial attempts to translate the crystallisation to batch led to challenges with loss of crystallinity and Hydrate2920 forming favorably in the presence of excess water. Using acetic acid as a dehydrating agent hindered formation of Hydrate2920 and furthermore allowed for direct conversion to CPOS-7. To allow for direct formation of CPOS-7 in high crystallinity flow chemistry was used for the first time to circumvent the issues found in batch. CPOS-7 and Hydrate2920 were shown to have promise for water and CO<sub>2</sub> capture, with CPOS-7 having a CO<sub>2</sub> uptake of 4.3 mmol/g at 195 K, making it one of the most porous CPOS reported to date.

Item Type: Article
Uncontrolled Keywords: crystalline porous organic salts, dehydration protocol, flow chemistry, high-throughput screening, porous materials
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 29 Sep 2023 15:29
Last Modified: 05 Dec 2023 22:17
DOI: 10.1002/chem.202302420
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