Preparation and characterization of triptycene-based microporous poly(benzimidazole) networks

Abstract

We demonstrate the synthesis of two triptycene-based microporous poly(benzimidazole) networks through condensation of triptycene-hexone with dialdehyde in refluxing glacial acetic acid containing ammonium acetate. The benzimidazole-linkage in the resulting polymers is confirmed by Fourier transform infrared and solid-state 13 C CP/MAS NMR spectroscopy. The spindle-shaped morphology of the obtained polymers was also observed through scanning electron microscopy. The materials, with Brunauer-Emmet-Teller (BET) specific surface area over 600 m 2 g À1 , possess a good hydrogen storage capacity (up to 1.57 wt% at 77 K and 1.0 bar) and a high carbon dioxide uptake (up to 14.0 wt% at 273 K and 1.0 bar). These excellent performances would probably make them promising candidates for gas-selective adsorption, heterogeneous catalysis, and proton-exchange membrane fuel cells.

Highly porous hydrogen-bond networks from a triptycene-based catechol

“…[6][7][8][14][15][16] These results, in conjunction with another recent study, 6 highlight that 1 is an attractive and synthetically accessible precursor towards that end. Our current work aims to use 1 as a component in more robust metal-organic assemblies and frameworks, with potential to combine porosity and redox-active properties.…”

“…[13][14][15] Diaminosubstituted phenylene residues in triptycenes are readily converted by Schiff base condensations into extended arenes, 16 annelated heterocycles 11,12 or polydentate metalbinding domains. [8][9][10] Alternatively, catechol functions in triptycene derivatives have been used as components in hydrogen-bonded supramolecular assemblies, or incorporated into larger crown ether receptors [1][2][3][4][5] or microporous polymer materials.…”

“…[8][9][10] Alternatively, catechol functions in triptycene derivatives have been used as components in hydrogen-bonded supramolecular assemblies, or incorporated into larger crown ether receptors [1][2][3][4][5] or microporous polymer materials. [13][14][15] Many of these studies make use of the rigid three-fold conformation of the triptycene moiety, which predisposes them to form cyclic or porous structures in molecular assemblies [1][2][3][4][5][6] or extended solids. 7,8,13,14,16 Following our interest in redox-active molecular architectures with bis-and tris-catechol components, 17,18 we identified 9,10-dimethyl-2,3,6,7,14,15-hexa(hydroxy)triptycene (1) and 9,10-dimethyl-2,3,6,7-tetra(hydroxy)triptycene (2; Scheme 1) 6 as potentially useful components in supramolecular assembly structures.…”

“…[13][14][15] Many of these studies make use of the rigid three-fold conformation of the triptycene moiety, which predisposes them to form cyclic or porous structures in molecular assemblies [1][2][3][4][5][6] or extended solids. 7,8,13,14,16 Following our interest in redox-active molecular architectures with bis-and tris-catechol components, 17,18 we identified 9,10-dimethyl-2,3,6,7,14,15-hexa(hydroxy)triptycene (1) and 9,10-dimethyl-2,3,6,7-tetra(hydroxy)triptycene (2; Scheme 1) 6 as potentially useful components in supramolecular assembly structures. We report here that solvate crystals of 1 adopt a number of novel hydrogen bonded network structures with substantial solvent-supported void space ‡.…”

Microporous Organic Polymers for Carbon Dioxide Capture

“…Additionally, it is not easy to control the bubbling of oxygen into the reaction system, which is necessary for the formation of imidazole ring. With these consideration in mind, Zhao et al [89] reported the synthesis of microporous poly(benzimidazole) networks through condensation reaction between dione, dialdehyde, and ammonium acetate. This approach is a template-free and catalyst-free condensation and produces no by-products.…”