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X-ray diffraction is used to study the sorption of CO and NO in two phthalocyanine nanoporous crystals (PNCs) with 4,4′ bipyridine or 4,4′ bipyrimidine trans coordinated to open Co2+ sites, demonstrating how the trans coordinated ligands influence the gas sorption properties and structures of the PNCs. [ABSTRACT FROM AUTHOR]

A key challenge in efficient molecular separation is fabricating large‐scale, highly selective polymeric membranes with precise pore control at the molecular scale. Herein, a new contorted monomer 6,6′‐dihydroxy‐2,2′‐biphenyldiamine (DHBIPDA) is introduced as a building block to generate cross‐linked, ultra‐thin microporous nanofilms (sub‐10 nm) via interfacial polymerization, enabling rapid, and precise molecular nanofiltration. Using diacyl chloride (TPC) as the cross‐linker instead of trimesoyl chloride (TMC) significantly reduces the pore sizes within the membranes and achieves a narrower pore distribution due to a semi‐crystalline structure. The film structures are confirmed using comprehensive characterization techniques including wide‐angle X‐ray scattering (WAXS), X‐ray diffraction (XRD), positron annihilation lifetime spectroscopy (PALS), CO2 adsorption analysis, and molecular‐scale simulation. The DHBIPDA/TPC and DHBIPDA/TMC membranes achieve methanol permeance values of up to 16.4 and 15.1 LMH bar−1 coupled with molecular weight cutoffs (MWCOs) as low as 283 and 306 Da, respectively. The DHBIPDA/TPC membrane demonstrates both higher permeance and higher selectivity compared to its relatively disordered counterpart DHBIPDA/TMC, consistent with characterization data. The DHBIPDA‐derived membrane efficiently separates dye mixtures with similar molecular weights and enables effective recycling of organometallic homogeneous catalysts, suggesting its potential for industrial applications. [ABSTRACT FROM AUTHOR]

Barium titanate (BTO) is well-known (as a photo- or sono/piezo-catalyst) to produce hydrogen peroxide via 2-electron reduction of oxygen in the presence of a sacrificial quencher, such as isopropanol. While barium titanate nanoparticles with a tetragonal crystal structure (piezoelectric) are particularly reactive, the recovery and reuse of these nano-catalysts from reactions can be difficult. Here, barium titanate nanoparticles of typically 200 nm to 600 nm diameter are embedded into a host film of a polymer of intrinsic microporosity (PIM-EA-TB). Due to molecular rigidity of the polymer, there is no capping effect, and the surface catalytic reaction occurs effectively with a catalyst embedded in the polymer. In this exploratory work, the catalytic formation of H2O2 in the presence of isopropanol is investigated via kinetic studies and by electron paramagnetic resonance (EPR). Perhaps surprisingly, at a neutral pH the rate of the catalytic reaction is substantially increased when barium titanate is embedded into the polymer host and when the polymer is protonated. This is attributed here to a "kinetic cage effect" which exploits the tertiary amine in the polymer backbone with anodic and cathodic processes coupled into a pH neutral reaction. [ABSTRACT FROM AUTHOR]

Polymers of intrinsic microporosity (PIMs) offer a useful combination of processability and inherent microporous features arising from their contorted and rigid structures, with the potential for the immobilisation of light harvesting groups for use in photochemistry. Herein, we report on the chemical incorporation of photosensitisers based on the benzo[c][1,2,5]thiadiazole (BTZ) group into PIM-EA-TB through a copolymerisation strategy, allowing up to 5% BTZ incorporation without compromising processability or microporosity. The BTZ-doped PIMs were then utilised as either homogeneous or heterogeneous visible light photosensitisers of oxygen under both batch and continuous flow conditions. The advantages of the solution processability of these materials was demonstrated by the simple deposition of the photoactive microporous polymer onto glass beads, which were then fixed within a column reactor for continuous flow photochemistry. [ABSTRACT FROM AUTHOR]

Ionic diodes are components in ionic circuits for AC‐electricity driven desalination and ion extraction processes. Independent of the ionic diode type/mechanism, achieving ionic current rectification at high ionic strengths is challenging but important, for example in seawater desalination and treatment of brine. Here, the butylation of a molecularly rigid (glassy) polymer of intrinsic microporosity (PIM‐EA‐TB) is shown to give anionic diodes with ultrahigh rectification effects (associated with interfacial resistivity) even in high ionic strength aqueous 2 M NaCl solution. The effect is rationalised based on polymer structure affecting ion transport. [ABSTRACT FROM AUTHOR]

In this work, a new polymeric binder (polymer of intrinsic microporosity, PIM‐1) has been investigated and discussed to prepare and characterize composite materials for the cathodic oxygen reduction reaction. The new binder is a polymer of intrinsic microporosity, a family of organic compounds with molecularly rigid (glassy) structure, good mechanical and chemical stability. Their influence on the electrocatalytic behaviour of a commercial electrocatalyst during the oxygen reduction reaction in acidic and alkaline media has been investigated, discussed and compared to the behaviour of common cationic and anionic polymer binders, using rotating disk electrode (RDE) techniques. Polymers of intrinsic microporosity perform similarly well, and sometimes better (due to rigidity and gas permeation) when compared to commercial binders. Thus, herein, we showed that PIMs do represent a very promising and versatile alternative as binders in electrocatalysis. [ABSTRACT FROM AUTHOR]

Metallic zinc has emerged as a promising anode material for high-energy battery systems due to its high theoretical capacity (820 mA h g-1), low redox potential for two-electron reactions, cost-effectiveness and inherent safety. However, current zinc metal batteries face challenges in low coulombic efficiency and limited longevity due to uncontrollable dendrite growth, the corrosive hydrogen evolution reaction (HER) and decomposition of the aqueous ZnSO4 electrolyte. Here, we report an interfacial-engineering approach to mitigate dendrite growth and reduce corrosive reactions through the design of ultrathin selective membranes coated on the zinc anodes. The submicron-thick membranes derived from polymers of intrinsic microporosity (PIMs), featuring pores with tunable interconnectivity, facilitate regulated transport of Zn2+-ions, thereby promoting a uniform plating/stripping process. Benefiting from the protection by PIM membranes, zinc symmetric cells deliver a stable cycling performance over 1500 h at 1 mA/cm² with a capacity of 0.5 mAh while full cells with NaMnO2 cathode operate stably at 1 A g-1 over 300 cycles without capacity decay. Our work represents a new strategy of preparing multi-functional membranes that can advance the development of safe and stable zinc metal batteries., (© 2024 Wiley‐VCH GmbH.)