Chiral Polymers of Intrinsic Microporosity: Selective Membrane Permeation of Enantiomers

Abstract

Following its resolution by diastereomeric complexation, 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (TTSBI) was used to synthesize a chiral ladder polymer, (+)-PIM-CN. (+)-PIM-COOH was also synthesized by the acid hydrolysis of (+)-PIM-CN. Following characterization, both (+)-PIM-CN and (+)-PIM-COOH were solvent cast directly into semipermeable membranes and evaluated for their ability to enable the selective permeation of a range of racemates, including mandelic acid (Man), Fmoc-phenylalanine, 1,1'-bi-2-naphthol (binol), and TTSBI. High ee values were observed for a number of analytes, and both materials exhibited high permeation rates. A selective diffusion-permeation mechanism was consistent with the results obtained with these materials. Their high permeability, processability, and ease of chemical modification offer considerable potential for liquid-phase membrane separations and related separation applications.

Homochiral MOF–Polymer Mixed Matrix Membranes for Efficient Separation of Chiral Molecules

“…Note that MIL‐53‐NH‐ l ‐His‐based MMMs exhibited a declining ee value as a function of time. A similar phenomenon has been commonly observed in solid‐state enantioselective membranes, in which a maximal enantioselectivity typically occurs during the initial stage of the separation, and the enantioselectivity gradually decreases with time due to the non‐selective diffusion of the competing enantiomer with weaker binding affinity …”

A highly rigid and gas selective methanopentacene-based polymer of intrinsic microporosity derived from Tröger's base polymerization

“…Since Polymers of Intrinsic Microporosity (PIMs) were rst reported in 2004, 1 a range of potential applications have been identied including catalysis, 2-5 chiral separations, 6 and as the active material in sensors 7,8 or ionic diodes. 9,10 In particular, PIMs with the ability to form exible, robust, self-standing lms have potential as membrane materials for anionic transport, 11 the separation of gases, vapours 12 or for nanoltration.…”

Carbonization of covalent triazine-based frameworks via ionic liquid induction

“…Porous organic polymers (POPs), an inorganic node free version of porous materials (including crystalline covalent organic frameworks (COFs), 6 and amorphous porous aromatic frameworks (PAFs), 7 polymers of intrinsic microporosity (PIMs), 8 porous polymer networks (PPNs), 9 covalent triazinebased frameworks (CTFs) [10][11][12][13][14][15][16][17][18][19] ) are attracting more and more attention because of their great potential for practical applications, for example, gas storage, separation, catalysis, and electronic device. 20 Among these materials, CTFs can be obtained by using a cheap catalyst such as ZnCl 2 and possess high chemical and thermal stability.…”