Substitution Effect Guided Synthesis of Task-Specific Nanoporous Polycarbazoles with Enhanced Carbon Capture

Resistive Memristors Using Robust Electropolymerized Porous Organic Polymer Films as Switchable Materials

Porous organic polymers (POPs) with inherent porosity, tunable pore environment, and semiconductive property are ideally suitable for application in various advanced semiconductor-related devices. However, owing to the lack of processability, POPs are usually prepared in powder forms, which limits their application in advanced devices. Herein, we demonstrate an example of information storage application of POPs with film form prepared by an electrochemical method. The growth process of the electropolymerized films in accordance with the Volmer-Weber model was proposed by observation of atomic force microscopy. Given the mechanism of the electron transfer system, we verified and mainly emphasized the importance of porosity and interfacial properties of porous polymer films for memristor. As expected, the as-fabricated memristors exhibit good performance on low turn-on voltage (0.65 ± 0.10 V), reliable data storage, and high on/off current ratio (104). This work offers inspiration for applying POPs in the form of electropolymerized films in various advanced semiconductor-related devices.

The mechanochemical synthesis of polymers

Mechanochemistry - the utilization of mechanical forces to induce chemical reactions - is a rarely considered tool for polymer synthesis. It offers numerous advantages such as reduced solvent consumption, accessibility of novel structures, and the avoidance of problems posed by low monomer solubility and fast precipitation. Consequently, the development of new high-performance materials based on mechanochemically synthesised polymers has drawn much interest, particularly from the perspective of green chemistry. This review covers the constructive mechanochemical synthesis of polymers, starting from early examples and progressing to the current state of the art while emphasising linear and porous polymers as well as post-polymerisation modifications.

Micro- and Ultramicroporous Polyaminals for Highly Efficient Adsorption/Separation of C1-C3 Hydrocarbons and CO2 in Natural Gas

This paper presents a series of micro- and ultramicroporous polyaminals with BET surface areas up to 1304 m² g^-1, which are prepared from two triazine-based tetraamines and three dialdehydes or monoaldehyde through the A₄ + B₂ or A₄ + B₁ aminalization reaction. It is interesting to find that the para-substituted monomers are favorable to force the linking struts apart in the network to generate micropores (1.22 nm), whereas the meta-substituted monomers make the pores in the network squeezed by the twisted linking struts, resulting in the formation of ultramicropores (0.52 nm). Besides, the adsorption behaviors of the major components of natural gas, such as propane (C₃H₈), ethane (C₂H₆), methane (CH₄), and carbon dioxide (CO₂), are significantly different, strongly depending on the polarizabilities, critical temperatures, molecular sizes of gases, porosity parameters of polymers, and the interaction between gases and the polymer skeleton. At 298 K/1 bar, the polymers show high uptake for C₃H₈ (114.5 cm³ g^-1) and C₂H₆ (84.2 cm³ g^-1). Moreover, the adsorption selectivities of C₃H₈/CH₄, C₂H₆/CH₄, C₃H₈/C₂H₆, C₃H₈/CO₂, C₂H₆/CO₂, and CO₂/CH₄ also reach 296.3, 23.1, 9.0, 22.1, 4.1, and 5.0, respectively, exhibiting promising applications in adsorption/separation of C₁-C₃ hydrocarbons and stripping CO₂ gas from natural gas under the ambient condition.

Conjugated nanoporous polycarbazole bearing a cobalt complex for efficient visible-light driven hydrogen evolution

A conjugated nanoporous polycarbazole (CNP) cross-linked by pyridine and coordinated to Co(iii) displays high catalytic performance for visible light-driven H₂ generation.

Carbazole-functionalized hyper-cross-linked polymers for CO2 uptake based on Friedel-Crafts polymerization on 9-phenylcarbazole

To systematically explore the effects of the synthesis conditions on the porosity of hyper-cross-linked polymers (HCPs), a series of 9-phenylcarbazole (9-PCz) HCPs (P1-P11) has been made by changing the molar ratio of cross-linker to monomer, the reaction temperature T 1, the used amount of catalyst and the concentration of reactants. Fourier transform infrared spectroscopy was utilized to characterize the structure of the obtained polymers. The TG analysis of the HCPs showed good thermal stability. More importantly, a comparative study on the porosity revealed that: the molar ratio of cross-linker to monomer was the main influence factor of the BET specific surface area. Increasing the reaction temperature T 1 or changing the used amount of catalyst could improve the total pore volume greatly but sacrificed a part of the BET specific surface area. Fortunately changing the concentration of reactants could remedy this situation. Slightly changing the concentration of reactants could simultaneously obtain a high surface area and a high total pore volume. The BET specific surface areas of P3 was up to 769 m2 g-1 with narrow pore size distribution and the CO2 adsorption capacity of P11 was up to 52.4 cm3 g-1 (273 K/1.00 bar).

Visible-Light-Enhanced Suzuki-Miyaura Reactions of Aryl Chlorides in Water with Pd NPs Supported on a Conjugated Nanoporous Polycarbazole

The visible-light-enhanced catalytic activation of aryl chlorides for Suzuki-Miyaura cross-coupling (SMC) reactions is highly challenging because of the strength of the C-Cl bond. In this work, palladium nanoparticles (Pd NPs) were grown on a conjugated nanoporous polycarbazole (CNP), named Pd/CNP. The hybrid material Pd/CNP could catalyze the SMC reactions of aryl chlorides with arylboronic acids in water under blue LED irradiation at room temperature with high efficiency. This protocol exhibited good functional group tolerance and the catalyst could be recycled without significant loss of its catalytic activity. CNP not only provided photogenerated electrons to enrich the electron density of the Pd NPs but also generated holes for the activation of the arylboronic acids.

Engineering nanoporous organic frameworks to stabilize naked Au clusters: a charge modulation approach

A simple charge modulation approach has been developed to stabilize naked Au clusters on a nanoporous conjugated organic network. Through engineering pore walls with regulated charges, the controllable growth of Au nanoclusters has been realized. The resulting supported catalyst exhibits excellent performance in the aerobic oxidation of alcohols.

Nitrogen-Rich Conjugated Microporous Polymers: Facile Synthesis, Efficient Gas Storage, and Heterogeneous Catalysis

Nitrogen-rich conjugated microporous polymers (NCMPs) have attracted great attention in recent years owing to their polarity, basicity, and ability to coordinate metal ions. Herein, three NCMPs, structurally close to polyaniline, were facilely synthesized via chemical oxidative polymerization between multiconnected aniline precursors. The NCMPs with high N content (11.84 wt %), intrinsic ultramicroporosity (<1 nm), and moderate surface area (485 m² g^-1) show wide-ranging adsorption functionality, e.g., CO₂ uptake (11 wt %) and CO₂-selectivity over N₂ (360, 1 bar), 1.0 wt % H₂ storage, as well as 215 wt % iodine vapor uptake at ambient pressure. Moreover, these NCMPs act as support for palladium catalysts and can maintain >94% activity in Suzuki-Miyaura coupling reactions after six continuous runs.

Solid-State Synthesis of Conjugated Nanoporous Polycarbazoles

A novel solid-state synthetic approach has been developed for the generation of conjugated nanoporous polymer networks. Using mechanochemical-assisted oxidative coupling polymerization, we demonstrated a rapid and solvent-free synthesis of conjugated polycarbazoles with high porosities and promising CO₂ storage abilities. This innovative approach constitutes a new direction for the development of novel nanoporous polymer frameworks through sustainable solid-state assembly pathways, and may open up new possibilities for the rational design and synthesis of nanoporous materials for carbon capture.

Pd-Metalated Conjugated Nanoporous Polycarbazoles for Additive-Free Cyanation of Aryl Halides: Boosting Catalytic Efficiency through Spatial Modulation

Transition-metal-catalyzed cyanation of aryl halides is a common route to benzonitriles, which are integral to many industrial procedures. However, traditional homogeneous catalysts for such processes are expensive and suffer poor recyclability, so a heterogeneous analogue is highly desired. A novel spatial modulation approach has been developed to fabricate a heterogeneous Pd-metalated nanoporous polymer, which catalyzes the cyanation of aryl halides without need for ligands. The catalyst displays high activity in the synthesis of benzonitriles, including high product yields, excellent stability and recycling, and broad functional-group tolerance.

Targeted control over the porosities and functionalities of conjugated microporous polycarbazole networks for CO2-selective capture and H2 storage

Target controllable conjugated microporous polycarbazole networks with pyridine-, bipyridine-, and cyano-functionalized networks exhibit a large surface area and tunable gas uptake.

Superacid-promoted synthesis of highly porous hypercrosslinked polycarbazoles for efficient CO2 capture

A superacid-promoted “knitting” strategy has been developed for the generation of hypercrosslinked nanoporous polycarbazoles for efficient CO₂ capture.

A facile route to prepare dimeric BODIPY-based porous organic polymers using FeCl3

A facile FeCl₃ catalyzed oxidation of the dimeric BODIPY monomers with different spacers to construct porous organic polymers have been reported. These polymers’ singlet oxygen generation capacities are dependent on the spacers.