Polymers of Intrinsic Microporosity Based on Dibenzodioxin Linkage: Design, Synthesis, Properties, and Applications

Abstract

The development of polymers of intrinsic microporosity (PIMs) over the last two decades has established them as a distinct class of microporous materials, which combine the attributes of microporous solid materials and the soluble nature of glassy polymers. Due to their solubility in common organic solvents, PIMs are easily processable materials that potentially find application in membrane-based separation, catalysis, ion separation in electrochemical energy storage devices, sensing, etc. Dibenzodioxin linkage, Tröger's base, and imide bond-forming reactions have widely been utilized for synthesis of a large number of PIMs. Among these linkages, however, most of the studies have been based on dibenzodioxin-based PIMs. Therefore, this review focuses precisely on dibenzodioxin linkage chemistry. Herein, the design principles of different rigid and contorted monomer scaffolds are discussed, as well as synthetic strategies of the polymers through dibenzodioxin-forming reactions including copolymerization and postsynthetic modifications, their characteristic properties and potential applications studied so far. Towards the end, the prospects of these materials are examined with respect to their utility in industrial purposes. Further, the structure-property correlation of dibenzodioxin PIMs is analyzed, which is essential for tailored synthesis and tunable properties of these PIMs and their molecular level engineering for enhanced performances making these materials suitable for commercial usage.

Removal of dyes using polymers of intrinsic microporosity (PIMs): a recent approach

“…have drawn significant research interest in different types of molecular separation processes including dye removal. 16–23 Based on the microporous nature, these materials are suitable for adsorption and nanofiltration of dyes. The aromatic building blocks in these materials can interact with dye molecules through π–π, dipole–dipole, ionic and ion–dipole interactions and the hydrophobic effect.…”

“…27 In addition to these attributes, PIMs have the additional advantage of easy processability, which is lacking in the case of MOFs, COFs and cross-linked polymers. 22,28 PIMs are one dimensional organic polymers containing interconnected micropores, and have emerged as potential materials for chemical separation in gas and liquid phases, heterogeneous catalysis, sensing, etc. 22,29 They are composed of structurally rigid building blocks with high aromatic expanses and have sites of contortions (usually tetrahedral centers or bridging units).…”

“…22,28 PIMs are one dimensional organic polymers containing interconnected micropores, and have emerged as potential materials for chemical separation in gas and liquid phases, heterogeneous catalysis, sensing, etc. 22,29 They are composed of structurally rigid building blocks with high aromatic expanses and have sites of contortions (usually tetrahedral centers or bridging units). 25 Because of the contorted structures, the aromatic groups cannot stack together, and the polymer backbones cannot pack efficiently in the solid state.…”

“…DBDO-based PIMs, which have been studied extensively, are prepared from biscatechol and aromatic tetrahalide based monomers via double aromatic nucleophilic substitution. 22 Condensation between aromatic diamines and formaldehyde is used to prepare Tröger's base PIMs through electrophilic aromatic substitution. 25 Polyimide linkages are obtained from the reactions of diamine and dianhydride precursors.…”

“…PIMs can be modified further through PSM to introduce various functionalities without affecting the structural integrity of the polymers. 22,30 A typical example of PIM is PIM-1, which happens to be the first reported PIM as well and it can be prepared in high molecular weight through base-mediated polycondensation of 5,5′6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane and 2,3,5,6-tetrafluoroterephthalonitrile monomers (Scheme 1a). 31 The nitrile group on PIM-1 can be postsynthetically modified to introduce a variety of functional groups (Scheme 1b).…”