Functionalized Conjugated Microporous Polymers

Conjugated microporous polytriphenylamine networks

Conjugated microporous polytriphenylamine networks with surface areas of 530 m² g⁻¹ were synthesized via Buchwald–Hartwig coupling, resulting in high CO₂ uptake (up to 6.5 wt%) and CO₂–N₂ selectivity (75) at 1 bar and 303 K.

Fast and facile fabrication of porous polymer particles via thiol–ene suspension photopolymerization

The porous particles were fabricated via thiol–ene click chemistry within 5 minutes under mild conditions.

Metal-organic frameworks capable of healing at low temperatures

Filling crystalline gaps with small molecules can drive interfacial healing between anisotropic solids. Sufficient mobility from these fillers allows the process to happen at a low temperature of -56 °C. Mended bulk crystals show modulus leap from 4 to 12 GPa and hardness from 400 to 1000 MPa.

Targeted synthesis of electroactive porous organic frameworks containing triphenyl phosphine moieties

A novel electroactive porous aromatic framework (JUC-Z4-Cl) was designed and synthesized via Yamamoto-type Ullmann cross-coupling reaction with the monomer tris(4-chlorophenyl)phosphine. By simple redox chemical reactions, stable, reductive, porous polytri(p-phenyl)phosphine (JUC-Z4) and polytri(p-phenyl)phosphine oxide (JUC-Z5) could be obtained as off-white powders. The structures of JUC-Z4 and JUC-Z5 were confirmed using magic-angle spinning nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, etc. The microporous architectures exhibit high stability (471°C for JUC-Z4 and 484°C for JUC-Z5) and large surface area (793 and 648 m² g⁻¹ for JUC-Z4 and JUC-Z5, respectively). JUC-Z4 also exhibits efficient recognition ability of greenhouse gases from dry air.

Catalysis by Covalent Organic Frameworks (COFs)

Porous covalent organic frameworks (COFs) are an emerging class of versatile materials. They provide novel possibilities for application as solid catalysts in heterogeneous catalysis due to their defined tailorable structures and surface chemistry, in combination with a high porosity. Thus, access to highly disperse catalytic centers is enabled and mass transport effects can be easily tuned. Catalytic active centers in COFs result from one of three different ways: (i) utilization of the porous frameworks as supports for metal nanoparticles or clusters with additional stabilization via coordination effects. (ii) Immobilization of molecular metal species within coordinating heteroatom moieties at well‐defined organic linkers, which is comparable to a heterogenization of homogeneous catalyst species. (iii) Intrinsic catalytic properties of metal‐free organic frameworks due to heteroatoms or defined functional groups especially in organocatalysis. In recent years many novel COF materials have been tested in various catalytic reactions proving their suitability as solid catalysts.

Fluorinated Porous Organic Polymers via Direct C-H Arylation Polycondensation

Considering the high reactivity of the C-H bonds in fluorobenzenes for direct arylation and special properties of fluorinated polymers, herein, synthesis of fluorinated porous organic polymers via direct C-H arylation polycondensation is explored. The obtained polymers (FPOP-1 and FPOP-2) are well characterized and show high porosities with Brunauer-Emmett-Teller specific surface area of above 1000 m² g^-1. Different pore size distribution (PSD) profiles of porous polymers can be obtained by selecting different core constructing monomers. FPOP-2 exhibits a relatively narrower PSD with the dominant pore size at about 0.63 nm, which is more suitable for adsorption of small gas molecules (H₂, CO₂, and CH₄) than FPOP-1. As a porous fluorinated hydrophobic material, FPOP-2 possesses high adsorption ability for toluene (976 mg g^-1 at saturated vapor pressure and room temperature) due to its high porosities and binding affinities between the guest molecules and the host network. The good sorption capacity of FPOP-2 for toluene makes it show potential applications in elimination of harmful small aromatic molecules in the environment.

Microporous organic polymers with ketal linkages: synthesis, characterization, and gas sorption properties

A series of microporous organic polymers with ketal linkages were synthesized based on the condensation of aromatic acetyl monomers with pentaerythritol. Fourier transform infrared and solid-state cross-polarization/magic-angle-spinning (13)C NMR spectroscopy were utilized to confirm the ketal linkages of the resulting polymers. The morphology can be observed from scanning electron microscopy and transmission electron microscopy images. The materials possess Brunauer-Emmet-Teller specific surface area values ranging from 520 to 950 m(2) g(-1), and the highest hydrogen sorption capacity is up to 1.96 wt % (77 K and 1.0 bar), which is superior to that of most of microporous organic polymers. The facile and cost-effective preparation process and excellent gas sorption properties make these kinds of materials promising candidates for practical applications.

Conjugated Porous Polymers For TNT Vapor Detection

A conjugated porous polymer (CPP) that exhibits fluorescence quenching when exposed to TNT vapor was synthesized via a Sonaogashira cross-coupling reaction. Two polymerization solvents, DMF and PhMe, and two activation procedures, evacuation and lyophilization, were evaluated to optimize the response of the CPP to TNT vapor. Key differences in surface area and absorption were seen as a function of polymerization solvent and activation procedure. The polymer synthesized in DMF and activated by lyophilization had the highest surface area and the strongest response to TNT vapor. This paper demonstrates the importance of growth and activation conditions in optimizing the porosity and sensing performance of CPPs.

From a supramolecular tetranitrile to a porous covalent triazine-based framework with high gas uptake capacities

Transformation of tetra(4-cyanophenyl)ethylene under Lewis acidic (ZnCl2) conditions at 400 °C leads to the formation of a porous covalent triazine-based organic framework (CTF) with a high surface area (2235 m(2) g(-1)), high CO2 and CH4 uptakes and the highest hydrogen uptake for a CTF material (1.86 wt% at 77 K, 1 bar).

Polymers of Intrinsic Microporosity

This paper focuses on polymers that demonstrate microporosity without possessing a network of covalent bonds—the so-called polymers of intrinsic microporosity (PIM). PIMs combine solution processability and microporosity with structural diversity and have proven utility for making membranes and sensors. After a historical account of the development of PIMs, their synthesis is described along with a comprehensive review of the PIMs that have been prepared to date. The important methods of characterising intrinsic microporosity, such as gas absorption, are outlined and structure-property relationships explained. Finally, the applications of PIMs as sensors and membranes for gas and vapour separations, organic nanofiltration, and pervaporation are described.

Porous, fluorescent, covalent triazine-based frameworks via room-temperature and microwave-assisted synthesis

Porous, fluorescent, covalent triazine-based frameworks (CTFs) are obtained in an unprecedentedly mild reaction, opening up a scalable pathway for molecular building blocks previously thought incompatible with this chemistry. Choice of monomers and synthetic conditions determines the optical properties and nano-scale ordering of these highly microporous materials with BET surface areas exceeding 1100 m(2) g(-1) and exceptional CO(2) capacities (up to 4.17 mmol g(-1)).

Versatile Postmodification of Conjugated Microporous Polymers Using Thiol-yne Chemistry

Radical thiol-yne chemistry is used for the modification of microporous networks with aliphatic alcohols. The degree of functionalization can be tuned by varying the reacted amount of thiol. Porosity analysis indicates that the microporosity can be preserved within a certain range, however, a decrease in pore size is observed.