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[Display omitted] New derivatives of dithiaazacrown ethers containing ψ-arylpyridine subunits were prepared based on the Hantzsch synthesis. The obtained compounds showed potential activities toward Hep-G2 cancer cell line, in both in silico and in vitro studies. The compounds were also good ligands for complex chemistry with metal ions due to possessing up to four heteroatoms and relatively big size of the crown ring. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting using renewable energy is considered a key technology to mitigate global warming and to realize the hydrogen economy. Extensive efforts have been devoted to finding high-performance electrode catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) involved in electrochemical water splitting, whereas the research on added components in the electrolyte to boost HER and/or OER is very limited. In this work, we report the use of 18-crown ether-6 (18C6) in the electrolyte as a bifunctional booster in water splitting. The addition of 18C6 in alkaline electrolyte drastically boosts HER current density from −50 to −300 mA cm−2 at −0.3 V vs. RHE and OER current density from 25 to 250 mA cm−2 at 1.7 V vs. RHE on the Ni foam electrode. Combing DFT calculations and experimental characterizations, the functions of 18C6 in boosting HER and OER on nickel electrodes under the alkaline condition are revealed. This research demonstrates the potential of macrocycle molecules as electrolyte additives and opens up new opportunities for boosting the performance of water splitting. The macrocycle molecule crown ether as an additive in the alkaline electrolyte boosts electrochemical water splitting by accelerating the kinetics of both HER and OER. [Display omitted] • Crown ether 18C6 in alkaline electrolyte boosts water splitting on Ni electrode. • HER current increases from −50 to −300 mA cm−2 at −0.3 V vs RHE. • OER current increases from 25 to 250 mA cm−2 at 1.7 V vs RHE. • Characterizations and DFT calculations are conducted to reveal the mechanisms. [ABSTRACT FROM AUTHOR]

[Display omitted] Aqueous Zn2+ ion batteries present notable advantages, including high abundance, low toxicity, and intrinsic nonflammability. However, they exhibit severe irreversibility due to uncontrolled dendrite growth and corrosion reactions, which limit their practical applications. Inspired by their distinct molecular recognition characteristics, supramolecular crown ethers featuring interior cavity sizes identical to the diameter of Zn2+ ions were screened as macrocyclic hosts to optimize the Zn2+ coordination environment, facilitating the suppression of the reactivity of H 2 O molecules and inducing the in-situ formation of organic–inorganic hybrid dual-protective interphase. The in-situ assembled interphase confers the system with an "ion-sieving" effect to repel H 2 O molecules and facilitate rapid Zn2+ transport, enabling the suppression of side reactions and uniform deposition of Zn2+ ions. Consequently, we were able to achieve dendrite-free Zn2+ plating/stripping at 98.4% Coulombic efficiency for approximately 300 cycles in Zn||Cu cell, steady charge–discharge for 1360 h in Zn||Zn symmetric cell, and improved cyclability of 70% retention for 200 cycles in Zn||LMO full cell, outlining a promising strategy to challenge lithium-ion batteries in low-cost, and large-scale applications. [ABSTRACT FROM AUTHOR]

Hyperkalemia is a common metabolic problem in patients with chronic kidney disease. Although oral medications and hemodialysis are clinically applied for lowering serum potassium, the intrinsic limitations encourage alternative therapy in the trend of adsorbent-based miniaturized blood purification devices. Cells serve as the biological K+ storage units that accumulate K+ through multiple mechanisms. Inspired by cells, our strategy aims at favorable permeation and enrichment of K+ in the microsphere. We incorporate cation-affinitive groups into core-shell structures with submicron-sized phase separation. These nano-spaced side-groups cooperate to form interlinked clusters, where crown ethers with Angstrom-scale ring for size-matched complexation, while ionic sulfonic acid groups for hydrophilicity and charge-buffering. The unique structure with such non-covalent interactions facilitates K+ for permeation across the shell and binding to the core while also ensuring mechanical strength and anti-swelling durability in biofluids. The microspheres exhibit high selectivity ratios of K+ (S K/Na , S K/Ca , S K/Mg up to 9.8, 21.6, and 17.7). As column adsorbents for hemoperfusion simulation, they effectively lower elevated K+ levels to the normal range (clearance rates up to 44.4%/45.3% for hyperkalemic human serum/blood). Blood compatibility tests show low protein adsorption, preferable hemocyte compatibility, and anticoagulation property in vitro. This promising strategy has clinical potential for hyperkalemia in high-risk patients. Hyperkalemia (serum potassium >5 mmol/L) is a common complication in chronic renal failure patients. The limitations of existing treatments prompt a shift to wearable artificial kidney technology for clinical convenience and efficacy. Existing treatments have limitations, and we turn to adsorbent-based miniaturized blood purification devices in the prospect of wearable artificial kidney technology. There exists a lack of ion-specific adsorbents applied in extracorporeal circuits to redress electrolyte imbalances like hyperkalemia. Inspired by cells, we aim at the favorable permeation and enrichment of K+ by microspheres. The microspheres have a microphase-isolated core-shell structure, whose nano-spaced groups form cation-affinitive clusters. Selective K+ removal and blood compatibility are achieved. We expect this strategy to enlighten alternative hyperkalemia therapy for these high-risk patients. [Display omitted] [ABSTRACT FROM AUTHOR]

Peroxisomes are essential metabolic organelles, well known for their roles in the metabolism of complex lipids and reactive ionic species. In the past 10 years, peroxisomes have also been cast as central regulators of immunity. Lipid metabolites of peroxisomes, such as polyunsaturated fatty acids (PUFAs), are precursors for important immune mediators, including leukotrienes (LTs) and resolvins. Peroxisomal redox metabolism modulates cellular immune signaling such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. Additionally, peroxisomal β-oxidation and ether lipid synthesis control the development and aspects of the activation of both innate and adaptive immune cells. Finally, peroxisome number and metabolic activity have been linked to inflammatory diseases. These discoveries have opened avenues of investigation aimed at targeting peroxisomes for therapeutic intervention in immune disorders, inflammation, and cancer. Peroxisomes are important metabolic regulators of immune cell development and function. Peroxisomes produce distinct lipids that control core cellular immune responses, including phagocytosis and secretion of inflammatory cytokines. Peroxisomes regulate cellular reactive oxygen and nitrogen species to modulate immune and inflammatory signaling. Intracellular pathogens interfere with peroxisomes in different ways to evade the peroxisome-dependent immune response and support their survival. Manipulation of peroxisome plasticity and metabolism may lead to novel therapeutics to treat immune disorders and antibiotic-resistant bacteria. [ABSTRACT FROM AUTHOR]

• Compilation of important results of investigations of the complexation chemistry, characterization, stability and photophysical properties of complexes of small ring benzo-oxa-crown ethers namely benzo15-crown-5, dibenzo-15-crown-5 and benzo-12-crown-4 with alkali metal ions in the solution state. • Results from techniques like UV, far-IR, Raman, 1H, 13C and multinuclei NMR that have been employed to confirm the formation of the complexes and designate their conformers in solution state are included in the review. • The solvent systems and binary and ternary mixtures of solvents employed to study these complexes have been reported in this review. • The complexation thermodynamics and results of experiments based on conductance properties, fluorescence responses and energy transfer mechanisms are also discussed in this paper. This review paper focuses on the past and recent investigations carried out in solution state to determine the complexation chemistry, characterization, stability and photophysical properties of complexes of small ring benzo oxa-crown ethers namely benzo - 15-crown-5, dibenzo-15-crown-5 and benzo-12-crown-4 with alkali metal ions. These crown ethers form stable complexes with physiologically important ions like Li+, Na+ and K +and mimic natural ionophores in this property. The experimental observations from UV–visible spectroscopy, IR spectroscopy, NMR spectroscopy, conductometry and calorimetry are useful in confirming the formation of these complexes. In addition to monitoring the complexation process, techniques like IR and NMR spectroscopy have helped to designate the conformers of the complexes in solution. These crown ethers have been used in developing functional materials such as ion sensors, fluorescent logic gates, oil/water emulsion separating agents and extractors of toxic ions like cesium from nuclear waste. The benzene moiety in these macrocycles enables them to act as fluorescent sensors for alkali metal ions. They make ideal candidates to anchor on nanoparticles for sensing alkali metal ions. The ring current in the benzene ring of benzo-crown ethers makes the carbon and protons nonequivalent and hence easily distinguishable by methods like 1H and 13C NMR spectroscopy as compared to 12-crown-4 and 15-crown-5. The solvent systems including binary and ternary mixtures of solvents employed in the study of these complexes have been reported in this review. Important aspects of complexation thermodynamics, fluorescence intensity altering processes and energy transfer mechanisms are also discussed in this paper. The dielectrics and donicity of the medium form an additional aspect of the review. These crown ethers form supramolecular assemblies with alkali metal halides and can therefore serve as good models to study and explore suitability of characterization methods for noncovalent interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Brief discussion of lithium reserves, resources, and technologies currently in practice toward extraction of lithium. • Exploration of lithium-selective organic receptors, their photo-physical studies, mechanism of interaction, and extraction from different sources. • Advantages of organic receptors and their scope towards lithium sensing and extracting from sea brine and battery e-waste. • Addressing challenges and presenting future perspectives for organic receptors towards extraction of lithium-ion on a large scale and even from dilute sources. The rising global demand for lithium and its compounds has led to a shift away from fossil fuels towards more energy-efficient systems like lithium-ion batteries (LIBs). Various technologies and materials are being explored for mining and extracting lithium, but current methods like solar evaporation and critical mining are slow and deplete resources rapidly. Therefore, there is a growing need for recycling used lithium. While some multi-passive technologies show promise, they often fall short in terms of cost-effectiveness, selectivity, and recyclability. Supramolecular receptors such as crown ethers, calixarenes, and their derivatives and more recently functionalized ionic liquids and deep eutectic solvents offer a potential solution to these challenges. Efforts are directed to create specialized supramolecular receptors that can both sense and extract lithium ion, particularly from challenging sources like sea-brine. Recent studies have highlighted the potential of silica-based materials and metal–organic frameworks (MOFs) in adsorption, but there is a need for further refinement to make them viable for real-world applications. Strategies involving post-modification and transforming receptors into MOFs or other materials hold promise in improving surface area and recyclability, thus enhancing their effectiveness. This review aims to compile all existing supramolecular receptors developed for lithium sensing and extraction, comparing them with newer generation receptors. It tries to summarize their selectivity towards lithium ions, describe their mechanisms, and extraction properties, providing a comprehensive resource for researchers working in this field. [ABSTRACT FROM AUTHOR]

The new class of ten macrocyclic compounds, lactic acid derived crown ethers, was designed and synthesized. They mainly composed of lactic acid and benzene or iodobenzene skeletons, and the introduction of iodine on the benzene ring was crucial to the formation of more regular crown ether conformation, starting from the diacid precursor. They possessed stable and larger cavities than classical macrocycles such as cyclodextrins. These crown ethers were discovered hiding function onto small molecules such as ethyl lactate, methanol, ethanol, aniline and phenol in nuclear magnetic resonance detection. [Display omitted] • New application of crown ethers in hiding small organic molecules. • The η was defined as the percentage of hidden molecules for the first time. • A new phenomenon in nuclear magnetic resonance testing. [ABSTRACT FROM AUTHOR]

Selective separation property enhancement is quite important for membranes separations, especially for high mass ratio Mg2+/Li+ separations. Low selectivity and unclear separation mechanism are the challenges for current membranes. In this study, we designed 4-aminophenyl-15-crown-5 incorporated polyamide nanofiltration membranes through interfacial polymerization for Li+ enrichment. The electrochemical tests and energy barrier calculations using transition state theory confirmed that the crown ether in nanofiltration membrane is responsible for governing Mg2+ transportation, resulting in a substantial energy barrier impeding its transport. Furthermore, a two-stage nanofiltration process was employed to enhance Li+ enrichment in simulated brine and achieved 35-fold increase in Li+ enrichment using as-fabricated membranes. These results demonstrate the substantial potential for Li + extraction from brine with a high Mg2+/Li+ mass ratio using the crown ether incorporated membrane. Meanwhile, the proposed strategy incorporating transport barriers presents a novel approach for designing ion-selective channels within membranes. [Display omitted] • A novel crown ether nanofiltration polyamide membrane was fabricated by interfacial polymerization (IP) process. • PEI@4A-B15C5 membrane has a great hindrance to Mg2+ transport. • Efficient enrichment of Li+ from a simulated brine. [ABSTRACT FROM AUTHOR]

A great challenge is to develop suitable techniques to extract Li+ resources from low-grade salt-lake brines with high Mg/Li ratios. In this study, an efficient ternary extraction system has been constructed using tributyl phosphate (TBP) and crown ether (CE) as the extractant and sodium bistrifluoromethylsulfonimide (NaNTf 2) as the auxiliary extractant to extract Li+. Results showed that the single-stage E Li % and SF Li-Mg were up to 74.1 % and 757, respectively, when the O/A was 1, 0.02 mol/l Li+ and 0.232 mol/l Mg2+. It is noteworthy that the elution of Li+ was also as high as 100 % at an O/A volume ratio of 5, when 0.5 mol/l HCl was used as the counter-extractant to recovery Li+. The NMR and FTIR analysis and molecular dynamics (MD) and density functional theory (DFT) revealed that the exceptional performance of the three-component extraction system was attributed to the optimal matching between the diameter of Li+ and the cavity size of the CE, as well as the strong affinity exhibited by CE, TBP, and NTf 2 − towards Li+. Specifically, the 2TBP-LiNTf 2 -CE-LiNTf 2 complex structure with the highest binding energy displayed the most structure. In summary, this work paves the way for the recovery of Li+ from low-grade salt-lake brine. [Display omitted] • The green ternary extraction system was constructed with TBP, CE and NaNTf 2. • The E Li % and SF Li-Mg of TBP-CE-NaNTf 2 were up to 74.1 % and 757, respectively. • The NTf 2 − readily forms the complexes with Li+ and TBP, CE. • The structure with 2TBP-LiNTf 2 -CE-LiNTf 2 is the most stable. • TBP and CE are more easily combined with NTf 2 − rather than Cl− to extract Li+. [ABSTRACT FROM AUTHOR]

• Sulfonated polyketone membranes functionalized with crown ethers are fabricated. • The synergistic ion channels are constructed by ion-binding and ion-exchange sites. • A separation factor for K+/Mg2+ over 40,000 in ion-distillation process is achieved. The specific interaction existing between crown ethers (CEs) and alkali metal ions serves a dual purpose in both facilitating the selective ion transport across polymeric membranes and exerting a significant influence on the microstructure by means of non-covalent interactions among the CEs. In this study, synergistic ion channels featuring a bi-periodic structure are constructed using both CEs and sulfonate (−SO 3 −) groups. It is observed that the membranes with reduced water uptake demonstrate enhanced ion permselectivity, attributable to the partial dehydration of ions during binding behavior. The bi-functional membranes exhibit excellent permselectivity for alkali metal ions, particularly K+, Na+ and Li+ ions, over Mg2+ ions. The permselectivity sequence of K+>Na+>Li+ and the notably superior K+/Mg2+ permselectivity, reaching up to 244.43, is attributed to the relatively stable CE-K+ complex within the channels, as supported by molecular dynamics simulations. Specifically, the fabricated membrane is successfully utilized in a 4-stage "ion-distillation" process, achieving an impressive separation factor for K+/Mg2+ over 40,000. The investigation of the synergy between CEs and anionic sites provides valuable insights for the development of cation-permselective membranes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Recent developments of chalcogen-based fluorescent probes for metal ion detection are reviewed. • Comparison of different chalcogens in the same detection system are discussed. • Design strategies of chalcogen-based fluorescent probes for metal ion detection are summarized. Metal ion detection is notably significant in fields such as the biological sciences, clinical medicine, environmental chemistry, and food safety. In this regard, fluorescent probes have represented an important technique for the rapid detection of metal ions in various areas. As Lewis bases, chalcogen elements with high electron-donating ability provide versatile detection targets for metal ion fluorescent probes. Such probes with chalcogens serving as recognition sites can be classified into coordination- and reaction-type devices. Notably, thiols; sulfides; thiocarbonyls; S-containing crown ethers, aromatic hydrocarbons, and peptides; and Se/Te-containing ligands can all serve as detection sites for these probes. O/N-containing ligands for coordination, fluorophores, and linkers all affect the electron-donating ability and selectivity of the coordination system. In this review, we discuss ongoing research efforts in this area and propose some design strategies for introducing chalcogen elements into metal ion fluorescent probes by integrating Lewis acid–base theory and comparative studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Technologies for lithium isotope separation based crown ether are reviewed. • Methods covered in this review include L-L extraction, S-L adsorption, chromatography. • Innovative technologies coupling crown ethers with others are summarized. • The advantages and challenges of these technologies are explained. • The directions for future research and development are identified. Nuclear energy is considered as the ultimate solution for future energy needs. High-purity lithium isotopes (6Li and 7Li) serve as the foundation raw materials for nuclear reactions. The development of environmentally friendly and efficient lithium isotope separation technologies plays an irreplaceable role in nuclear energy. Utilizing crown ethers for the selective complexation of metal ions has been proven to be a highly promising method for lithium isotope separation. In this review, various lithium isotope separation methods based on crown ether chemistry, including liquid–liquid extraction, solid–liquid adsorption, ion-exchange chromatography, membrane adsorption, and membrane chromatography techniques are introduced. The technologies coupling crown ethers with other separation methods, such as ionic liquid extraction and electric field migration, are summarized. The principles underlying lithium isotope separation are discussed from various perspectives. Finally, the current challenges and issues in lithium isotope separation research are described, and the future prospects for utilizing crown ethers in lithium isotope separation are outlined. To sum up, the review provides insights on crown ether chemistry and relative technologies for industrial-scale lithium isotopic enrichment in future nuclear energy research. [ABSTRACT FROM AUTHOR]

[Display omitted] • The free rotation of p-benzyl could make Cr6-Bz-DGA better match to REEs(III) of different ion radii with different binding mode. • The aza-crown ether of ligand provided 3 coordination atoms for smaller ionic radii Y(III)/Lu(III) and 6 atoms for larger ionic radii La(III). • The binding capacity of complexes with smaller ionic radii REEs(III) were stronger than complexes with larger ionic radii REEs(III) due to larger charge density. • The NMR titration experiment further proved M/L = 2:2 (aza-crown ether-REEs(III)-DGA connection) was the thermodynamic product. The development of new ligands is crucial for the functional application of REEs(III), because the coordination compounds of rare-earth elements (REEs) have many important applications in pharmaceuticals and nuclear medicine. In this paper, a novel ligand (Cr6-Bz-DGA) with the aza-crown ether and diglycolamide (DGA) units was designed to coordinate with light, medium, and heavy REEs(III). It was found that M/L = 2:2 species (aza-crown ether-REEs(III)-DGA connection) was the thermodynamically stable complex. The stability constants of Nd(III), Eu(III), and Ho(III) complexes were determined by UV–Vis and fluorescence titration, respectively, which were log β Nd = 7.49 ± 0.019, log β Eu = 7.10 ± 0.013 and log β Ho = 8.27 ± 0.032. The variation of fluorescence lifetime suggested that the Eu(III) ion was exclusively coordinated by the ligand with coordination number 9 in the inner sphere of the Eu(III) ion. The shifts of 1H NMR revealed that there are different coordination between the ligand and REEs(III). For larger ionic radii La(III), three O atoms of the DGA unit and five O and one N atoms of the aza-crown ether unit were supplied. While, for Y(III)/Lu(III) with smaller ion radii, the ligand supplied three O atoms from the DGA and one N atom and only two O atoms from the aza-crown ether. The displacement experiment of REEs(III) combined with ligand and the fitted stability constants prove that the smaller ionic radii REEs(III) more strongly bind with ligand than larger ionic radius REEs(III). These results may help understand the coordination behavior of REEs(III) and expand their potential applications. [ABSTRACT FROM AUTHOR]

A fascinating 18-crown-6-ether appended 25-oxasmaragdyrins (Cr-Prs) compound is investigated by doping alkali metal ions (Na+, K+), alkaline earth metal ions (Mg2+, Ca2+) and transition metal ions (Zn2+, Cd2+, Hg2+) to the crown ethers. Interestingly, the Hg2+@Cr-Prs compound exhibits a tremendous second-order nonlinear optical (NLO) property compared to other metal doping. Thus, the Cr-Prs can be used as efficient NLO-based metal ion detectors, and these results will broaden the scope and the efficiency of ion detection. [Display omitted] • Interestingly, the M n+@Cr-Prs undergo significant shrinkage of the crown ether, and the dihedral angle (Anglea) also changes after doping with metal ions. • Obviously, the natural population analysis (NPA) charge shows that the charge distribution of the compounds is regulated by the metal ions. • Significantly, the incorporation of metal ions, especially Hg2+ ion regulates and enhances effectively the first hyperpolarizabilities (β tot). • Moreover, the evolutions of unit sphere representation (USRs), the two-level model and the absorption spectra can well explain the tendency of β tot values. Crown ethers, known for their efficacy as metal ion traps, have garnered significant interest in optoelectronic applications due to their unique cavity structure and special binding ability with metals. Herein, we systematically designed and investigated the second-order nonlinear optical (NLO) properties of an intriguing compound, 18-crown-6 derivative appended with 25-oxasmaragdyrins (Cr-Prs), achieved through the incorporation of diverse metal ions into the crown ether ring. Significantly, the β tot values of compounds with alkaline earth metal ions (Mg2+, Ca2+) are greater than those compounds with alkali metal ions (Na+, K+). Interestingly, the Hg2+@Cr-Prs compound exhibits a tremendous second-order NLO property with the β tot value of 5.34 × 105 au. Further insights into substantial β tot values across all compounds were provided through a comprehensive analysis of the transition energies, the molecular orbitals, and the absorption spectra of the main excited states. The calculation results conclude that the second-order NLO properties of Cr-Prs can be modulated by incorporating metal ions into the crown ether ring. Crown ether emerges as a facilitator in detecting and identifying Hg2+ ions, serving as an effective NLO-based ion detector. These findings not only broaden the scope of cation detection and efficiency but also present innovative applications in analytical and optoelectronic research, encapsulating the essence of our study within a concise framework. [ABSTRACT FROM AUTHOR]

• Artificial transmembrane ion channels based on supramolecular macrocycles have been successfully synthesized. • The channels with different chain lengths are constructed by the central acyclic cucurbituril and bilateral crown ethers. • The artificial transmembrane ion channels exhibit good transport efficiency for K+ and Na+ ions. • Artificial transmembrane ion channels with different chain lengths have varying effects on the transport of ions. Compared with natural channel proteins, artificial transmembrane channels based on macrocyclic molecules offer several advantages, including low price, stable properties, ease of structure modification, and functionalization. These benefits are highly significant for research purposes. Following this approach, a series of unimolecular ion channels have been designed and synthesized using crown ether and acyclic cucurbituril. The structure of the artificial channels was confirmed by NMR and HR-MS spectra. These unimolecular transmembrane channels have demonstrated effective efficiency in inserting into the lipid bilayers and transporting alkali metal cations, which can be substantiated through comprehensive fluorescence experimentation. Additionally, the alkali metal cation transport efficiency of the artificial channels is tunable by varying the length of the linkers between crown ether and acyclic cucurbituril. Thus, this study not only presented a simple and feasible unimolecular channel that could transport sodium and potassium selectively but also provided a simple model for constructing complex and controllable artificial transmembrane channels. [ABSTRACT FROM AUTHOR]

[Display omitted] • A colorimetric chemosensor for the detection of Cr(III) and Co(II) chloride in the presence of LMI was synthesized. • The acceptable LODs as 0.58 and 0.90 μM were validated in isopropanol for Cr(III) and Co(II), respectively. • A TLC test strip was successfully employed for the visible multication detection by L. • Dispersion of L in water was shown as a selective FL chemosensor of Cr(III). The present study describes the chemosensing capability of an N 2 O 4 -donor tetrabenzodiaza-crown ether macrocyclic ligand derivatized by two pyridine side arms to afford the flexible macrocyclic ligand, 5,20-bis(pyridin-4-ylmethyl)-5,6,12,13,19,20,26,27octahydrotetrabenzo [e,i,o,s][1,4,11,14]tetraoxa[7,18]diazacycloicosine (PMHBOA). A selective colorimetric behavior of PMHBOA for the prompt detection of Cr(ΙΙΙ) and Co(ΙΙ) can be observed with naked eyes. The 1H, 13C{H} NMR, and infrared spectroscopy disclosed the ligand binding capability for selective metal ions, ascribed to a 1:1 complex formation with Cr(III) and Co(II) cations in isopropanol. The limit of detection (LOD) values were calculated as 580 and 850 nM for Cr(ΙΙΙ) and Co(ΙΙ), respectively, accompanied with suitable LOQs as 1.95 µM for Cr(III) and 2.85 µM for Co(II), respectively. The reusability was confirmed in the presence of ethylenediaminetetraacetic acid (EDTA). Moreover, a TLC-based fabricated paper strip successfully applied PMHBOA as a chemosensor for synchronous visible detection of Cr(III) and Co(II) in their alcoholic solution. Meanwhile, the observed color change along with the turn-off fluorescent of PMHBOA guaranteed a felicitous choice of candidate for Cr(III) in the presence of other library metal ions in isopropanol:H 2 O (9/1 v/v) solution. A fast separation test on the filter paper, impregnated with PMHBOA, was also employed to separate Cr(III) and Co(II) cations from aqueous solutions by recording UV–vis spectra. The 1H NMR spectroscopy supported the macrocycle ring and side arms as the parallel coordination site of PMHBOA with Cr(III) and Co(II). [ABSTRACT FROM AUTHOR]

• Synthesis new perfluoro(phosphonic acid)s. • Grafting the side chains of a perfluoropolymer. • New perfluoro(phosphonic acid)s against hydroxyl radical degradations. • Vindicating the vulnerability of fluoroalkyl ether groups in Nafion from hydroxyl radical attacks. Nafion™ utilizes -SO 3 H groups for proton conduction. Using an alternative proton-exchange functionality like -PO 3 H 2 , -COOH, etc., to replace -SO 3 H in ion conductive fluoropolymers has attracted significant attention. For example, composite membranes comprising Nafion™ and perfluoro(carboxylic acid) bearing a -COOH group on its side chains have been used in color-alkali cells to reduce unwanted electrolyte crossovers. In the present paper, we reported a new synthetic strategy for constructing novel -PO 3 H 2 -bearing fluoropolymers (FBP). Our method employs a ZnI 2 -promoted phosphorylation reaction of triethyl phosphite that converts benzyl alcohol on a side chain of a fluoropolymer into a benzylphosphodiester group, followed by trimethylsilyl chloride (TMSCl) hydrolysis to yield FBP. This strategy has enabled us to graft a fluoropolymer side chain directly with phosphonic acid. Although the in-plane proton conductivities of FBP fluoropolymers are lower than those of Nafion™ 115, most FBPs, especially Homo-FBP that has no fluoroalkyl ether group on its side chains, are significantly more stable against hydroxyl radical degradations in Fenton tests. This paper presents a new method for the synthesis of -PO 3 H 2 -containing fluoropolymers and our work also confirms a novel strategy for enhancing the long-term stability of a proton-conductive fluoropolymer in electrical devices—eliminating or reducing fluoroalkyl ether groups on the side chains of the polymer. [Display omitted] [ABSTRACT FROM AUTHOR]

• Proposed a simpler scheme for preparing membranes using non-covalent interactions. • A composite membrane provides excellent rejection and large water permeability. • CE@GO membrane for highly selective removal by crown ether pore size effect. The highly efficient sieving of Cs+ from natural brine resources has garnered considerable attention for the extraction of cesium raw materials. However, for the trade-off between ion rejection and water permeability, it remains challenging for graphene oxide (GO) membranes to improve efficient sieving of Cs+ with a large water permeance. Here, we have successfully addressed this challenge by fabricating a GO membrane that incorporates crown ether (CE) through π-π and CH-π interactions with GO sheets. This CE intercalation has resulted in a significantly enhanced Cs+ sieving capability from salt lake brines, concurrently improving water permeance. The unique Cs+ selective cavity structure of the CE has enabled the GO membrane to exhibit a Cs+ rejection rate of 94.4 % and a water permeance of 15.8 L m−2 h−1 bar−1 at a Cs+ concentration of 0.150 mmol/L (∼20 ppm). Compared to the pure GO membrane, these results represent an improvement of over 70 % in Cs+ rejection and more than 230 % in water permeance. Interestingly, we have also observed that this GO membrane exhibits a low Na+ system consisting of two components, the separation factor of Cs+/Na+ reaches up to 5.0, which is significant in monovalent ionic membrane separations. These significant discoveries provide a promising strategy for the highly efficient extraction and concentration detection of Cs+ from complex ion solutions. [ABSTRACT FROM AUTHOR]

Designing a highly selective and fast separation membrane is critical to realize H 2 -sieving with efficient performance, which is still a challenge by far. In this study, we combine molecular dynamics (MD) and first-principle approaches to investigate the H 2 separation property of graphene crown ether. Our MD results demonstrate that graphene crown ether exhibits a superior H 2 -sieving performance under various temperatures and external pressures, allowing fast passage for H 2 while completely rejecting CH 4. The H 2 permeability exceeds 105 GPU at selectivities exceeding 1500. These results highlight an outstanding performance of crown ether pores for separating H 2 from mixtures with CH 4. Observed from MD simulation trajectories, this highly selective separation is caused by the intrinsic dimensional difference between the two types of gases and the pore. The first-principle calculations further confirm that it is energetically more favorable for H 2 to transit the graphene crown ether than for CH 4. Our findings suggest a novel application of the graphene crown ether in H 2 -sieving with great promise for future membrane designs. • H 2 /CH 4 separation by graphene membranes embedded with crown ether. • Graphene crown ether nanopores realize the highly efficient and selective sieving of H 2 from mixture of CH 4. • Graphene crown ether achieves the pure H 2 gas after sieving. • Exploration from molecular level by using molecular dynamics simulation and first-principle approaches. [ABSTRACT FROM AUTHOR]

[Display omitted] New polycyclic aromatic derivatives annulated both with thiophene and with 15-crown-5 ether moieties, crown naphthothiophenes, were synthesized via the Mallory photocyclization with the use of iodine as the mild oxidizer, while two isomeric products were readily separated by column chromatography. Their complexation with Ba2+ and Mg2+ cations was examined by both optical and electrochemical methods. Spectroelectrochemical studies indicate that the obtained compounds, depending on their structure, can be chemically stable in the oxidized state [ABSTRACT FROM AUTHOR]

In this paper, self-made diformyl-dibenzo-18-crown-6 ether (DDB 18 C 6) is in-situ grafted into the pores of mesoporous molecular sieve (SBA-NH 2), and then the aforementioned modified molecular sieve (SBA-C) is introduced into the polyvinyl alcohol solution, and then the glutaraldehyde as the crosslinking agent to synthesized the anion exchange membrane under for fuel cell application. During the experiment, a series of anion exchange membranes (P-(SBA x% -C), x is the mass fraction of SBA-NH 2) is developed and the pore channels and chemical structures of the aforementioned membrane is verified by FT-IR, SAXD, N 2 adsorption-desorption, 1H NMR and XPS. Moreover, the performance of the membrane synthesized in this paper is also investigated and the results revealed that the unique membrane internal structure can improve the OH− transportation efficiency. Furthermore, the ionic conductivity of P-(SBA 10% -C) membrane is the highest (0.107S·cm−1) and the power density is the highest (354.8 mW cm−2) at 80 °C. By immersing P-(SBA 10% -C) membrane in 6 mol L−1 KOH solution for 168 h, the conductivity at 80 °C only decreased by 2%, proving that P-(SBA 10% -C) has a higher conductivity, good single cell performance and alkali stability. [Display omitted] • A new kind of mesoporous molecular sieve with ordered pores grafted with crown ether was prepared. • A new type of anion exchange membrane with ordered mesoporous channels grafted with crown ether was prepared. • Using crown ether to complex K+ to improve the conductivity of anion exchange membranes. • Prepared membrane showed excellent OH− conductivity and alkaline stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • DAB was grafted on 14C4PI for improving Li+ adsorption. • The CE loading on the nanofiber membrane reached from 1.38 to 2.27 mmol/g. • The adsorption capacity of Li+ was enhanced from 40.17 to 60.71 mg/g. • The separation factor for Li+/Mg2+ was up to 37.46. • The adsorption energy of DAB-g-14C4PI to Li+ was higher than that of 14C4PI. The global demand for lithium is increasing rapidly with the blossom of the new energy field. It is imperative to develop a sustainable and efficient approach for recovering Li+ resources from salt-lake brine. In this study, diamino dibenzo-14-crown-4 ether (DAB) was chemically grafted on 14-crown-4 polyimide (14C4PI) by nucleophilic substitution to fabricate nanofiber membrane by electrospinning method. The crown ether loading of DAB-g-14C4PI membrane was increased from 1.38 up to 2.27 mmol/g, and the grafting degree reached 83.4 % by regulating the additive amount of DAB and the reaction time. The Li+ equilibrium adsorption capacity of the DAB-g-14C4PI nanofiber membrane was enlarged from 40.17 (14C4PI) to 60.71 mg/g. The adsorption for Li+ on the membrane was a monolayer chemical adsorption process proved by the adsorption kinetic and isotherm models. The separation factors of the membrane for Li+/Na+, Li+/K+, Li+/Mg2+ and Li+/Ca2+ were 69.24, 79.4, 37.46 and 67.53, respectively. DFT calculations indicated the raised Li+ adsorption capacity was also ascribed to the enhanced adsorption energy from −107.71 to −122.84 kcal/mol, owing to the relatively higher electric charge density (−0.478 vs −0.448 a.u.). In summary, this work put forward a novel method to fabricate a nanofiber membrane with a high crown ether loading for the extraction of lithium resources. [ABSTRACT FROM AUTHOR]

Curcumin has excellent anti-tumor activity, but its instability at physiological pH, low bioavailability and poor targeting limit curcumin to further become an excellent anticancer drug. In this study, two curcumin/ nido -carborane fluorescent polymers, curcumin-borane-crown ether coated by sodium alginate (SA-CBC) and curcumin-borane-crown ether (CBC) , were prepared, and SA-CBC with better properties to be the most promising anti-tumor drugs. Crown ether/sodium alginate drug delivery strategies can improve the release property of curcumin. Nido -carborane enhances the targeting of curcumin and the inhibiting effect on tumor cells. After testing, the fluorescence lifetime of SA-CBC was 4.72 ns, indicating good fluorescence properties. In vitro drug release results showed that the constructed drug delivery system released curcumin at a controlled rate. The results of transmission electron microscopy and particle size showed that SA-CBC was well encapsulated, with a particle size of less than 200 nm, easy to be absorbed in vivo. Bioactivity studies showed that SA-CBC had a strong affinity and inhibiting effect on tumor cells, and the inhibition rate could reach 84.5 %. In conclusion, this study provides an innovative protocol for the design of curcumin anticancer drugs and lays the foundation for the development of more effective anti-tumor drugs with small side effects. [Display omitted] • Using dendritic polymer based on crown ether/sodium alginate as delivery vehicle of drug. • The biostability and bioavailability of curcumin have been greatly improved. • Achieving a pH-sensitive and controlled release effect. • Cell imaging was performed to visualize cell permeability. • Bioactivity studies show strong inhibiting effect on tumor cells. [ABSTRACT FROM AUTHOR]

Portable fluorescence-based Cs+ radionuclide sensing has received great concerns yet challenged by interference in complex sample matrices. Herein, a reliable method was established by in situ converting the preconcentrated Cs+ to CsPbBr 3 perovskite nanocrystals in mesoporous silica modified with dibenzo 24-crown-8 ethers (DB24C8E-SiO 2), which combined the selective extraction of Cs+ with in situ fluorescence derivatization to achieve good anti-interference ability. The high adsorption capacity (49.5 mg g−1) of DB24C8E-SiO 2 for Cs+ and elution-free operation enabled enrichment factor up to 4500, which was conducive to reducing the limit of detection (LOD) for Cs+. By this method, the fluorescence intensity linearly increased with the Cs+ concentration from 0.050 μg mL−1 to 100 μg mL−1 with an LOD of 0.017 μg mL−1 (S/N = 3). The concentration of Cs+ in seawater sample was detected to be 0.056 μg mL−1. The recoveries of Cs+ in spiked samples remained above 88.90 % and the relative standard deviations were less than 12.06 %. In addition, the relative errors of this method were within ±13.2 % compared with the result from atomic absorption spectrometry. The study demonstrated the high potential of the method for removal and portable detection of Cs+. [Display omitted] • Solid phase extraction coupled with in situ perovskite growth are realized for highly selective Cs+ sensing. • On site fluorescence derivatization enables ultrahigh enrichment factor and low detection limit. • Fluorescence turn-on and wavelength-shift responses facilitate visual sensing. [ABSTRACT FROM AUTHOR]

Hydration of In3+ is the main factor limiting its extraction efficiency from an aqueous solution during a liquid-liquid extraction process. In this study, KCl was introduced into the aqueous solution to facilitate the formation of InCl 4 − of low charge density, which is expected to possess much weaker hydration compared with In3+, promoting the solvent extraction of indium. The crown ethers (CEs) with varied cavity sizes, benzo-18-crown-6 (B18C6), benzo-15-crown-5 (B15C5), and benzo-12-crown-4 (B12C4), were synthesized. The extraction performance of the CEs toward indium in the presence of sufficient KCl in the aqueous solution was investigated. The liquid-liquid extraction process was analyzed theoretically based on density functional theory (DFT) from the aspects of thermodynamics, geometric structure optimization, electrostatic potential (ESP), and independent gradient model (IGM). The theoretical evaluations agreed well with the experimental results that the hydration of indium could be significantly weakened through the formation of InCl 4 − and the complexation ability of the CEs toward indium is in the order of B18C6 > B15C5 > B12C4. The complexation mechanism between the CEs and indium during the extraction process was further explored with the assistance of 1H NMR spectrum and SEM-EDS. The results indicate that crown ether coordinates with K+ to form [CE-K]+ at the two-phase interface, which further associates with InCl 4 − to create the complex of CE-KInCl 4 , realizing the efficient indium extraction. Moreover, B18C6 showed excellent selectivity toward In3+ over the competing ions such as Fe3+, Al3+, Zn2+, Sn2+ and Ca2+ in a complex system. Indium could be efficiently recovered from the loaded organic phase by using 1 M HCl as the stripping agent with a stripping efficiency of 98.1%. [Display omitted] • Hydration of indium was effectively weakened through transformation of In3+ to InCl 4 −. • Various crown ether extractants were designed and synthesized for indium uptake. • Extractability of crown ether was evaluated through solvent extraction experiments. • Complexation mechanism was clarified through DFT calculations and 1H NMR titrations. • B18C6 is able to efficiently extract indium forming the stable B18C6-KInCl 4 complex. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel benzo-12-crown-4 and β-diketone bi-functionalized ionic liquids [(B12C4)C n im][TTA] were synthesized. • A new [(B12C4)C 6 im][TTA]-[C 6 mim][NTf 2 ] extraction system was developed for lithium extraction from alkaline solution. • [(B12C4)C 6 im][TTA] exhibited a wide pH working range (4.0–11.0) and high lithium extraction efficiency. • [(B12C4)C 6 im][TTA] demonstrated superior separation factors of Li/Na (β Li/Na = 2154.0) and Li/K (β Li/K =757.2). • The extraction mechanism involving cation exchange was determined. Indeed, the efficient and sustainable recovery of lithium from highly concentrated sodium-containing mother liquors of Li 2 CO 3 and salt-lake brines remains a significant challenge. Herein, two typical Li+ recognition receptors, namely benzo-12-crown-4 and thenoyltrifluoroacetone, were separately introduced into the cationic and anionic parts to successfully synthesize novel bi-functionalized task-specific ionic liquids [(B12C4)C n im][TTA] (n = 4, 6, 8). A new, green, and high-efficiency extraction system has been developed by dissolving [(B12C4)C 6 im][TTA] in commercial room-temperature ionic liquid 1-hexyl-3-methyl-imdazolium bis(trifluromethylsulfonyl)imide [C 6 mim][NTf 2 ], without the addition of any other co-extractants. The newly developed [(B12C4)C 6 im][TTA]-[C 6 mim][NTf 2 ] extraction system exhibited a wide pH working range (4.0–11.0), high lithium extraction efficiency (95.4 %), as well as superior separation factors of Li/Na (β Li/Na = 2154.0) and Li/K (β Li/K =757.2). The extraction mechanism involving cation exchange was determined through slope analysis, ion chromatography, UV–vis spectroscopy and FT-IR spectra measurement, indicating that one [(B12C4)C 6 im][TTA] molecule can interact with two lithium ions and form a 1:2 complex. Moreover, the [(B12C4)C 6 im][TTA]-[C 6 mim][NTf 2 ] extraction system also demonstrated fast extraction kinetics, facile stripping and regeneration, along with good cycling performance. Furthermore, a multi-stage countercurrent extraction process to extract lithium from the simulated mother liquor of Li 2 CO 3 was evaluated. When the volume ratio (O/A) of oil phase (O) to water phase (A) was 1.0, only two theoretical extraction stages were needed to extract 91.4 % of lithium into the organic phase. Thus, the [(B12C4)C 6 im][TTA]-[C 6 mim][NTf 2 ] extraction system is promising for lithium extraction from mother liquor of Li 2 CO 3 and salt-lake brines. This study also opens the avenue for designing cationic and anionic bi-functionalized ionic liquids for metal ion separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new strategy of soft membrane based molecular recognition was proposed. • Recognition of anions on surface of hydrochloric acid is controllable by shear flow. • Hydration shells of easily hydrated anions are easily recognized. • Shear flow has an influence on recognition of the hydration configuration of anions. • Molecular recognition of anions depends on the hydration ability of anions. Understanding the self-assembly behavior of macrocyclic molecules under shear flow and its impact on the mass transfer of target ions near the liquid–liquid interface is of great importance in host-guest chemistry and mordern separation processes. In this work, a new strategy based on soft-film molecular recognition (SF-MRT) was proposed to investigate the effect of aqueous shear flow on specific recognition of octahedral RhCl 6 3-, octahedral PtCl 6 2-, and planar quadrilateral PdCl 4 2- anions with different hydration configurations using 18-crown-6 as an extractant spreaded on the surface of concentrated hydrochloric acid. Remarkably, the SF-MRT process achieved an extraction order of RhCl 6 3- > PdCl 4 2- > PtCl 6 2-, whereas the impregnated resin coated with a layer of oil film containing 18-crown-6 yielded a reverse extraction order of PtCl 6 2- > PdCl 4 2- > RhCl 6 3-. Experimental results demonstrated the functional group (-SO 3 Na+) present on the surface of the resin particles exhibits a preferential adsorption of H 3 O+ ions through the cation exchange mechanism, resulting in crown ether molecules only recognizing H 3 O+ ions, and subsequently facilitating the preferential extraction of PtCl 6 2- anions by 18-crown-6·H 3 O+ through the ionic association mechanism. However, during the SF-MRT process, the hydrophilic and flexible cavity formed by the ether oxygen group (-O-) in crown ether molecules primarily recognizes the water molecules in the hydration shell surrounding platinum metal anions due to the lower concentration of H 3 O+ dissociated on the surface of concentrated hydrochloric acid. Compared to the sparse water molecules around the hydrated PtCl 6 2- anions, the dense water molecules around the hydrated RhCl 6 3- anions are more easily recognized. The directional and flexible hydrogen bond network formed between the crown ether molecules and platinum metal anions through the "water bridges" interaction is more amenable to be controlled by the laminar shear flow beneath the thin-layer extractant oil film. This discovery lays the foundation for the development of new flexible and controllable molecular recognition methods. [ABSTRACT FROM AUTHOR]

A variety of group 1 organometallics complexes were synthesized using two iminophosphoranomethanide ligands with differing steric properties. An in-depth structural and spectroscopic analysis was carried out, together with DFT analysis, to probe the nature of the metal-carbon interactions. [Display omitted] Herein we report the synthesis of three sets of alkali metal complexes with the iminophosphoranomethanide ligands {CH(SiMe 3)P(Ph) 2 NSiMe 3 }− (TMSNPC-H) and {CH(SiMe 2 t Bu)P(Ph) 2 NSiMe 3 }− (TBDMSNPC-H), the latter of which is first reported here. The compounds of general formula [M(RNPC-H)] (3-M and 4-M ; M = Li, Na, K) were obtained via a protonolysis reaction between an alkyl reagent (n -butyllithium, benzylsodium, or benzylpotassium) and the proligand. All resulting compounds were characterized by multinuclear NMR, IR spectroscopy, elemental analysis and single crystal X-ray diffraction. We also attempted to prepare the separated ion pairs of [M(TMSNPC-H)] with the matched crown ethers, and obtained the 'ate' complexes [Li(12-crown-4) 2 ]+[Li(TMSNPC-H) 2 ]− (5-Li) and [Na(15-crown-5) 2 ]+[Na(TMSNPC-H) 2 ]− (5-Na), the coordination polymer [{K(18-crown-6) 2 }{K(TMSNPC-H)(18-crown-6)}(TMSNPC-H)] ∞ (6) and separate ion pair complex [K(15-crown-5) 2 ]+[TMSNPC-H]− (7). 5-Li is an unusual lithium-lithiate crown ether species, whilst 5-Na represents the first example of a sodium-sodiate crown-ether complex. [ABSTRACT FROM AUTHOR]

[Display omitted] We herein report the formation of the cyclic dimeric silver(I) complexes and the selective organic guest recognition. The reaction of pillar[5]-bis-crown with AgPF 6 afforded a cyclic dimeric supramolecular complex [Ag 4 (L) 2 (H 2 O) 2 (CH 3 CN) 2 ](PF 6) 4 in which the silver(I) atoms exist inside the crown ether cavities. The cyclic dimeric silver(I) complex reacts with 1,2-dicyanoethane (C2) to form a guest-inclusion complex [Ag 4 (C2 @ L) 2 (CH 3 CN) 2 ](PF 6) 4 , exhibiting its formation being controlled by the length of the guest molecules used. Additionally, the silver(I) supramolecular complex demonstrated molecular recognition for C2 in both solution and solid states. [ABSTRACT FROM AUTHOR]

• Rare earth compounds with non-coordinating anions. • Potential for further reactivity in catalysis. • Highly reactive rare earth ions complexed by crown ethers. The efficacy of Me 3 NHBPh 4 as a protolytic agent in the generation of reactive lanthanoid cations has been further explored. Reaction of [Nd(BH 4) 3 (thf) 4 ] with Me 3 NHBPh 4 in a 1:3 mole ratio, and dibenzo-18-crown-6 (DB18C6) in thf did not yield [Nd(thf) n ][BPh 4 ] 3 , but [Nd(BH 4) 2 (DB18C6)][BPh 4 ]⋅2THF (1), a complex primed for further functionalisation, was isolated. The structure has an eight coordinate Nd atom with two trans tridentate BH 4 − ligands. Redox transmetallation/protolysis (RTP) reactions between Yb metal, PhHgC 6 F 5 , and Me 3 NHBPh 4 in the presence of 18-crown-6 (18C6) or DB18C6 in MeCN or in thf followed by work up with MeCN yields [Yb(CE)(MeCN) 3 ][BPh 4 ] 2 ⋅nMeCN (CE = 18C6, n = 0 (2), and DB18C6 n = 3 (3)), the structures of which have nine coordinate Yb atoms. Two pairs of MeCN ligands are transoid , whereas the third pair have a small cis N Yb N angle. In the absence of a crown ether ligand, the RTP reaction in MeCN yields the known [Yb(MeCN) 8 ] [BPh 4 ] 2. The efficacy of Me 3 NHBPh 4 as a protolytic agent in the generation of reactive lanthanoid cations has been further explored. Reaction of [Nd(BH 4) 3 (thf) 4 ] with Me 3 NHBPh 4 in a 1:3 mole ratio and dibenzo-18-crown-6 (DB18C6) in thf yielded [Nd(BH 4) 2 (DB18C6)][BPh 4 ]⋅2THF (1). Redox transmetallation/protolysis (RTP) reactions between Yb metal, PhHgC 6 F 5 , and Me 3 NHBPh 4 in the presence of 18-crown-6 (18C6) or DB18C6 in MeCN or in thf followed by work up with MeCN yields [Yb(CE)(MeCN) 3 ][BPh 4 ] 2 ⋅nMeCN (CE = 18C6, n = 0 (2), and DB18C6 n = 3 (3)), the structures of which have nine coordinate Yb atoms. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A well demonstration of DFT potential to assess the enhancement of Nonlinear optical response of 15CR5 based complexes in relation to pure 15CR5. • Elucidation of doping effect of selected alkaline earth metals on Nonlinear optical properties of 15CR5 molecule. • Alkaline earth metals like Be, Mg and Ca enhance the Nonlinear optical properties of 15CR5 significantly. Crown Ether (15CR5) molecule is a worthwhile organic material exhibiting excellent NLO properties and characteristics. In this research, density functional theory (DFT) was extensively employed to study the nonlinear optical (NLO) properties of alkaline earth metal doped 15CR5 by using WB97XD/6-31G+(d, p). Binding energies, interaction energies, vertical ionization energies and reactivity parameters unveiled the thermodynamic stability of these systems. These molecules show a lower value of HUMO-LUMO energy gap indicating their superior electronic properties. Moreover, these complexes possess high oscillator strength and lower excitation energies displaying their better electrical and optical characteristics than pure 15CR5. Non-covalent analysis was carried out for all the designed systems forecasted the van der wall interactions between 15CR5 and dopants. These complexes in the visible region have excess electrons that are highly absorbed in the range of 405.73 to 608.27 compared to 15CR5. The Hyperpolarizability (β tot) of these designed materials was in the range of 9097.21–21627.85 au which is significantly higher than its pure counterpart. Results based on the density of state (DOS), natural bond orbital analysis (NBO) and transition density matrix (TDM) were also strongly supported the enhancement of the NLO properties of these systems. These newly designed alkaline earth metal doped 15CR5 systems with promising NLO characteristics can be used for optoelectronic applications. [ABSTRACT FROM AUTHOR]

To ensure efficient ion transport in anion exchange membranes (AEMs) for hydrogen production, it is essential to develop efficient ion transport pathways. Utilization of intermolecular interactions induced by embedded macrocycles is an attemptable approach. Self-aggregated channels can be constructed with this force serving as a driving force for stepped-up ion transport. Herein, we present a delicate strategy to polymerize the macro crown ether in the backbone and graft flexible alkyl long chains to prepare comb-type copolymers as AEMs. The macrocycle dynamically traps ammonium ions as an anchor which accelerates the aggregation of ionic phases. The resulting AEMs show favorable membrane-forming ability and tensile strength. As the side chain length increases, the microphase-separated morphology develops well and formed 'belt'-like channels in the poly(terphenyl piperidone)-5-bis-quaternary ammonium (PTCP-5-bisQA) membrane, exhibiting a hydroxide conductivity of 78.1 mS/cm at 80 °C. The alkaline durability of PTCP-5-bisQA AEM is explored by nuclear magnetic hydrogen spectrum (1H NMR) investigation at 80 °C for 720 h. Furthermore, the PTCP-5-bisQA based electrolyzer reaches a current density of 330 mA/cm2 at 1.85V by 1 wt% potassium hydroxide solution circulation. A life endurance observation is carried out on this electrolyzer for a 100h operation with performance degradation rate of 40.1 mV/h. Comb-shaped PTCP-x-bisQA AEM with insert macrocycle have been organized into well-defined micro-morphology for efficient hydroxide transport and AEMWE operation. [Display omitted] • The macrocyclic crown ether was nested into backbone to dynamically trap ions. • Long side chain induced nanophase separation facilitates fast ion conduction. • Improved conductivities were acquired accompanied with low dimensional swelling. • The AEMWE performance was demonstrated in 1 wt% KOH solution circulation. [ABSTRACT FROM AUTHOR]

The construction and application of macrocycle-assembled AIE- SPNs. [Display omitted] • Macrocycles-assembled AIE- SPNs coalesced the merits of AIE, macrocycles and supramolecular polymer networks. • Macrocycles-assembled AIE- SPNs show nice prospect in various fields. • Recent progress on constructing and application of macrocycle-assembled AIE- SPNs has been summarized. • The mechanisms on self-assembly, AIE, stimuli-response and structure–property/application relationships are discussed. • Supply new perspectives to solve problems by the synergy of AIE, SPNs and macrocycles through supramolecular approach. Supramolecular polymer networks (SPNs) possess abundant stimuli-responsive properties due to their reversible non-covalent assembly features, and could be used to build various smart materials. Meanwhile, aggregation-induced emission (AIE), a characteristic optical phenomenon, shows splendid prospect in a wide range of areas. The rapid development of AIE provides a novel chance for the functionalization of SPNs. In addition, macrocycles, each of them possessing their own unique merits, play a key role in constructing various functional supramolecular systems. Hence, the coalescence of macrocycle, AIE and SPNs into the macrocycle-assembled AIE- SPNs greatly expanded the properties and applications of this kind of supramolecular systems. Therefore, macrocycle-assembled AIE- SPNs have attracted more and more attentions. In this review, the mechanisms on self-assembly, AIE, stimuli-responses as well as host–guest interactions have been carefully summarized. Moreover, the structure-effect relationships including cavity size, non-covalent interaction, the type of macrocycles, structures of networks and structures of guest compounds have been discussed. The construction methods, properties and applications of macrocycles-assembled AIE- SPNs have been systematically introduced according to the type of macrocycles including crown ether, cyclodextrin, calixarene, cucurbit[n]uril, pillar[n]arene and other novel macrocycles. Moreover, the challenges and bright future of macrocycle-assembled AIE- SPNs also have been described. [ABSTRACT FROM AUTHOR]

• Acyclic and cyclic crown ethers derived indole were designed and synthesized in moderate to high yields in simple way. • Acyclic crown ethers 31–36 and 52–54 show highy selectivity and stability toward harmful and toxic metal ions of Hg+2. These results suggested that these ligands could potentially be used as Hg2+ selective receptors. • Most of acyclic and cyclic crown ethers derived indole revealed very potent inhibitory activity against AChE and BuChE. Particularly, compound 16 most potently inhibited AChE with IC 50 value of 0.244 mM, being 149.6-fold more selective for AChE than BuChE. • In silico molecular docking using the CDocker tool confirmed the mechanism of action of compound 16 which has been successfully docked into the binding pocket of AChE protein. A series of new thiacrown ethers 14–16, 18 – 22 and acyclic thiacrown ethers (podands) 31–36 and 52–57 derived indole were synthesized and characterized by NMR and mass spectrometric techniques. Preliminary complexation study of podands 31–36 and 52–54 with some metal cations was studied using a conductometric method in acetonitrile at 25 °C. After the addition of acetonitrile solution of 31–36 or 52–54 podands to the metal cation acetonitrile solutions, the conductance was strongly decreased only in the presence of Hg2+ ions. The order of the stability constants of 1:1 podands–Hg2+ complexes is in the order: 52 > 53 > 35> 31> 32> 36> 33. On the other hand, podands 34 and 54 formed 1:2 podands–Hg2+ complexes. Thiacrown ethers 14–16, 18 – 22 and acyclic thiacrown ethers 31 – 36 , and 52 – 57 were evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes in vitro. The results indicated that compounds 14 – 57 demonstrated more potent inhibitory effects on AChE compared to BuChE, with IC 50 values ranging from 0.244 to 1.359 mM and 1.270 to 81.473 mM, respectively. Notably, compound 16 most potently inhibited AChE with an IC 50 value of 0.244 mM, being 149.6-fold more selective for AChE than BuChE. The presence of imine, ester groups, and sulfur, as well as oxygen or bromine atoms in the cyclic thiacrown ethers, improved their inhibitory activity against both AChE and BuChE. Inhibition of AChE by compounds 19, 20, 54 , and 56 ranged from recovery levels of over 50 % to 74.2 %, while inhibition of BuChE by compounds 18, 19, 31, 32, 55 , and 56 ranged from 48.2 % to 79.3 %. These findings underscore the potential of azinethiacrown ethers and acyclic thiacrown ethers as promising candidates for further exploration in the context of AChE and BuChE inhibition. In silico molecular docking using the CDocker tool confirmed the mechanism of action of synthetic compound 16 which has been successfully docked into the binding pocket of AChE protein with the highest score of 42.36 in comparison with the rest of the compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A new TBP-IL-CE system was used for efficient extraction of Li+ from salt lake brine. • The single-stage Li+ extraction rate was 89.5 % and the selectivity of Li/Mg reached up to 515. • The high Li+ recovery and Li/Mg selectivity was due to the H-bond improved CE coordination. • The complex ratios of TBP/CE, and Li were 2 and 1 through extraction dynamic analysis. The high similarity in chemical properties between Li+ and Mg2+ poses a substantial challenge for their selective separation from salt lake brine with high Mg-Li (m/m) ratios. Herein, a highly efficient solvent extraction system was reported for Li+/Mg2+ selective separation, with tributyl phosphate (TBP) and di(aminobenzo)-14-crown-4 (CE) as extractants, [C 4 mim][NTf 2 ] (IL) as co-extractant, and methylene chloride as a diluent. Simulated brines included 0.01 M LiCl and 0.01 and 0.2 M MgCl 2 with Mg/Li mass ratios of 3.5 and 70, respectively. Molecular dynamics (MD), density functional theory (DFT), and 1H NMR analysis were employed to reveal the hydrogen bond interaction and compatibility between CE, TBP, and IL. Under the optimal extraction conditions containing a concentration of 20 mg/mL CE and 0.61 mmol/mL IL, the maximum single-stage Li+ extraction rate of the TBP-CE-IL extraction system with Mg/Li mass ratios of 3.5 and 70 were 89.5 and 81.8 %, and the separation factor of Li to Mg were up to 515 and 422. Compared with the TBP-IL extraction system, the addition of CE effectively improved the extraction rate of Li+ and the selectivity of Mg-Li, which was due to the hydrogen bond interaction between CE and TBP/IL and the cavity size effect between CE and Li+, improving CE coordination and endowing the complex generated in the organic phase with greater stability. The possible structure of the complex in the organic phase was determined to be 2TBP·Li·NTf 2 -CE·Li·NTf 2 through Li+ extraction dynamic analysis. In summary, this work provides an efficient separation technology for Li+ extraction from salt lake brine. [ABSTRACT FROM AUTHOR]

[Display omitted] • The complexes displayed emissions attributable to 3LC and 3MLCT transitions. • They gave quantum yields between 0.0072-0.0088, long lifetimes and large Stokes shifts. • Their CVs displayed a reversible reduction wave and an irreversible oxidation wave. • Their reduction waves are more positive than their corresponding ruthenium analogues. • The promising photophysical properties make them suitable for chemosensing application. Crown ethers and their derivatives are known to coordinate metal cations and organic molecules. They have an adaptable ring-opening diameter, which makes their complexations very selective. In this work, a series of rhenium (I) tricarbonyl complexes (C1–C3) based on oxathiacrown ethers conjugated with 1,10-phenanthroline (L1–L3) were designed and prepared. They were characterized by elemental analysis, spectral and electrochemical methods. They displayed microanalytical, NMR and mass spectral data consistent with their formulations. Electronic absorptions associated with 1MLCT transitions were observed at ca. 400 nm in the complexes. Their emission spectra displayed a low intensity peak at ca. 451–467 nm and a high intensity peak at ca. 605–608 nm. The low intensity peak appearing at high energy may be assigned to 3LC while the high intensity peak appearing at low energy may be assigned to 3MLCT transition. The complexes exhibited quantum yields between 0.0072 and 0.0088, lifetime measurements of 41–48 ns and large Stokes shifts at ca. 8500 cm−1. The CV of the complexes displayed one reversible ligand-centered reduction wave at ca. −1.6 V and an irreversible metal-centered oxidation wave at ca. 1.1 V (vs Ag/AgNO 3). No remarkable changes were observed in the photophysical and electrochemical properties of the complexes upon increasing the macrocyclic cavity. The promising photophysical properties make them suitable candidates for application in chemosensing. [ABSTRACT FROM AUTHOR]

Efficient management of the high-level liquid waste (HLW) generated during the reprocessing of nuclear fuel involves mutual separation and transmutation of the minor actinides like Am and Cm, which are chemically very similar. The structure–activity relationships between the extractants and their separation performances are expected to provide practical approaches for designing proficient ones for actinide separation. The rigidity in the ligand backbone as well as the coordination environment created by the side groups play an important role in such separations. Macrocyclic ligands such as crown ethers with hydrophilic groups are also used for the separation of transplutonium actinides. In the present work, an in-silico analysis of the bonding of Am(III) and Cm(III) ions with donor center modulated azacrown based ligand, i.e., a ligand formed by replacing the four 'O's of the azacrown macrocycle in N,N′-bis[(6-carboxy-2-pyridyl)-methyl]-1,10-diaza-18-crown-6 (L1) with four 'S's (L2) is carried out using relativistic density functional theory to develop a deeper understanding of the impact of both, soft donors as well as the cavity effects on the separation of these metal ions. The subtle differences in the bonding is brought about by the covalent interaction of the metal and the aza-macrocyclic O and S donors. The electron donation from the ligand is mostly accepted in the metal 6d orbitals and minimally to the 5f orbitals. But the f-orbital participation plays the crucial role in bringing about the subtle difference in the bonding between Am(III) and Cm(III) ions with the ligands. The trivalent Cm ion with half-filled initial f7 configuration shows resistance in participating in bonding as was observed from NPA, QTAIM, NBO and DOS analyses. Whereas, the Am(III) ions having f6 configuration are eager to accept f-electrons to achieve the stable half-filled configuration. The energetics elucidated that both L1 and L2 ligands are Am selective. But the extraction capacity and selectivity is higher for the L2 ligand. The Am selectivity can be attributed to the significant covalent interaction of S donors which have better electron donating capacity (than O) to the electron deficient Am(III) ion. The use of soft donor atoms viz. S in a crown ether like environment along with hard carboxylate Os for chelation of trivalent Am and Cm is established to bring about promising selectivity for the former, along with enhanced extractability. Designing of new ligands with similar features in the future with modulated softness of donor centres can be anticipated to bring about further improvedselectivity between these two nearly identical minor actinide ions. [Display omitted] [ABSTRACT FROM AUTHOR]

A series of novel hybride chiral macrocyclic compounds is described. The macrocyclic core of the new compounds is decorated with monoterpene fragments and includes 2 imine nitrogens and 2 tertiary amine nitrogens of the N,N-piperazine linkage as well as several repeating ethyleneoxy units resembling those of crown ethers. The macrocyclic compounds are prepared in moderate preparative yield (16–31%) upon treatment of a mixture of bis(α-amine oximes) and α,ω-dichloro derivatives of tri-, tetra- and hexa-ethylene glycol with sodium methylsulfinylmethylide. Chemical structure of the new macrocycles was established by a complex of spectroscopic techniques and X-ray analysis. The new macrocyclic compounds demonstrate remarkable selectivity with respect to Pd(II) and Au(III) and are able to efficiently extract these metals from acidic media containing a complex mixture of alkali metals, 3 d -elements and noble metals. The features of conformational behavior, the ability to form complexes and the selectivity of extraction were studied using quantum chemical calculations at the DFT level. Based on the data obtained, a consistent scheme has been formulated to explain the features of extraction and the extraction selectivity of individual macrocycles. [Display omitted] [ABSTRACT FROM AUTHOR]

• The reactivities of ester oxygens are greater than those of ether oxygens. • The electrostatic potential indicates synergistic interactions of functional groups and predicts initial complexation sites. • The Hirshfeld charge can only be used to analyze the reactivity of a single oxygen atom. Lithium plays a vital role in the development of batteries. The synergistic effect of the functional groups in crown ethers was analyzed to determine the mechanism for the selective adsorption of Li+ in solution. The results show that the ester oxygen atoms are more reactive than the ether oxygens. The Hirshfeld charges are suitable for evaluating the reactivities of individual atoms. The electrostatic potential illustrates the synergistic interactions of functional groups and predicts the initial complexation sites. The binding energies demonstrate that the most stable complexes are formed on the ether ring. Moreover, for all of these complexes, the C–O bond lengths of the C–O---Li+ system are increased by the Li+-O interaction. The Li+ separation efficiency of the armed crown ether is only 8.07 % and increases to 56.72 % with the addition of phenol. The increased extraction efficiency is reflected by the binding energies of the complexes. [ABSTRACT FROM AUTHOR]

This review critically examines the effectiveness of ion-imprinted membranes (IIMs) in selectively recovering lithium (Li) from challenging sources such as seawater and brine. These membranes feature customized binding sites that specifically target Li ions, enabling selective separation from other ions, thanks to cavities shaped with crown ether or calixarene for improved selectivity. The review thoroughly investigates the application of IIMs in Li extraction, covering extensive sections on 12-crown-4 ether (a fundamental crown ether for Li), its modifications, calixarenes, and other materials for creating imprinting sites. It evaluates these systems against several criteria, including the source solution's complexity, Li+ concentration, operational pH, selectivity, and membrane's ability for regeneration and repeated use. This evaluation places IIMs as a leading-edge technology for Li extraction, surpassing traditional methods like ion-sieves, particularly in high Mg2+/Li+ ratio brines. It also highlights the developmental challenges of IIMs, focusing on optimizing adsorption, maintaining selectivity across varied ionic solutions, and enhancing permselectivity. The review reveals that while the bulk of research is still exploratory, only a limited portion has progressed to detailed lab verification, indicating that the application of IIMs in Li+ recovery is still at an embryonic stage, with no instances of pilot-scale trials reported. This thorough review elucidates the potential of IIMs in Li recovery, cataloging advancements, pinpointing challenges, and suggesting directions for forthcoming research endeavors. This informative synthesis serves as a valuable resource for both the scientific community and industry professionals navigating this evolving field. [Display omitted] • MST-based IIMs: Promising for scalable Li recovery. • Investigates maximum Li + adsorption of 157 mg g−1. • Calls for refining IIM synthesis for higher capacity. • Suggests bespoke monomers for targeted Li + capture. • Highlights IIMs' potential in heavy metal recovery. [ABSTRACT FROM AUTHOR]

[Display omitted] • 14C4PI nanofiber membrane was prepared for efficient Li+ recovery from LiBs. • The membrane with a fine diameter exhibited a high adsorption capacity for Li+. • 14C4PI membrane displayed a high selectivity of Li+ to Na+, K+, Mn2+, Co2+ & Ni2+. • The complex-ratio of crown ether in 14C4PI (1.38 mmol g−1) to Li+ reached 1.46:1. • Gibbs free energy change of 14C4PI-Li+ complex was the highest (−113.99 kcal mol−1). To meet the growing demand for lithium resources, it is ideal to develop a green and efficient approach for recovering lithium resources from discarded lithium-ion batteries. In this work, nanofiber membranes of 14-crown-4-ether polyimide (14C4PI) (M n = 33 kDa) with the crown ether loading of 1.38 mmol g−1 in the main chain were fabricated by electrospinning and the structure of the nanofiber membrane was regulated by tuning the electrospinning parameters. The selectivity adsorption of 14C4PI nanofiber membrane was investigated in the simulated extract of discarded lithium-ion batteries. The results showed that the 14C4PI-12 nanofiber membrane with a high specific surface area of 41.27 m2/g and a diameter of 122.7 nm was successfully prepared under the operating conditions (polymer concentration of 12 wt%, voltage of 30 kV, flow speed of 1 mL h−1, tip-to-collector of 100 mm). The 14C4PI-12 nanofiber membrane displayed a high equilibrium adsorption capacity for Li+ (Q m = 40.17 mg g−1). The adsorption of Li+ onto the membrane was proven to be monolayer chemical adsorption confirmed by adsorption kinetics and isotherm models. The calculated equilibrium adsorption rate (EAR) was up to 70 % and the complex-ratio of crown ether in 14C4PI to Li+ was 1.46:1, whose theoretical value is 1:1. Meanwhile, the selective separation factor of Li+ to Na+, K+, Mn2+, Co2+, and Ni2+ were up to 52.3, 54.97, 48.82, 41.05 and 35.04, respectively, which were much higher than that obtained from other selective adsorption method reported in literatures. The density functional theory (DFT) calculations confirm that the superior selectivity of 14C4PI to Li+ is attributed to the higher Gibbs free energy change of 14C4PI-Li+ complexation (−113.99 kcal mol−1). To sum up, this work provides an efficient method to fabricate crown ether functional polymer nanofiber membrane for recycling lithium resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Long-lived radionuclides intrude into the environment after nuclear accidents. • Crown ethers with appropriate cavities can selectively separate radionuclides. • Crown ether-based adsorbents are effective at removing radionuclides from waste. • Future research ideas involving crown ether-assisted radionuclide removal. Concerns about hazardous long-lived radionuclides (RNs) in the environment have fueled interest in selectively separating RNs, particularly in the aftermath of the Chornobyl and Fukushima disasters. The current review focuses on the use of crown ethers (CEs) to separate long-lived radioisotopes, such as cesium, strontium, and technetium, from aqueous matrices. The review guides the selection of appropriate CEs for developing efficient absorbents, providing valuable insights for separating and analyzing RNs in environmental matrices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Crown ether and benzothiazole coupled donor–acceptor ligands for highly selective towards Cu2+ ion. • Distinctive yellow colour from colourless solution without any interference. • The limit of detection for L1 is 5.48 × 10−6 M, and L2 is 8.57 -× 10−6 M. • L1 and L2 act efficiently for the naked eye as a Cu2+ ion sensor. • Recoveries in real-time samples were about 98% and 99% for ligands. • Theoretical computation showed that Cu2+ sensing mechanism of L1 and L2; the results show a metal-to-ligand and ICT takes place. A Crown ether and benzothiazole coupled ligands L1 (D-A) and L2 (A-D-A) have been synthesized and characterized through a standard analytical technique. A UV–visible spectrum-based colorimetric analysis has validated the cation-ligand binding affinity. Both L1 and L2 have shown high selectivity towards Cu2+ ion with the distinctive yellow colour from colourless solution without any interference with the competing metal ion, and it was found that the limit of detection for L1 is 5.48 × 10−6 M, and L2 is 8.57 × 10−7 M, also the binding constant for L1 is 6.4 × 101 M−1, and L2 is 3.5 × 102 M−1. The sensing mechanism was elucidated through job's plot and computational studies where the stoichiometric ratio of 1:1 and 1:2 for L1 and L2 well coordinated with Cu2+ ions. The formation of bonds between the metal and ligand exhibited a reduced band gap compared to the free ligands, which evidenced metal mediated intra ligand charge transfer (ICT) process due to ligand–metal interaction. Test strips and water samples analysis was also performed to determine the efficacy of the probe's ability to detect copper ions in real-time samples. L1 and L2 act efficiently as a Cu2+ ion sensor for the naked eye and it is the work's key accomplishment. [ABSTRACT FROM AUTHOR]

Carbon dioxide, as an industrial waste gas, has a severe impact on the climate. Thus, efficient catalytic conversion of CO 2 has attracted considerable attention worldwide. In this study, a series of crown ether-conjugated microporous polymer materials containing carboxylic groups (CCMPs) were synthesized through multi-components reactions in one pot. This synthesis involved the reaction of dialdehydebenzo-18-crown-6 with different monomers of amino and pyruvate in the presence of DDQ. Fourier transform infrared spectroscopy, carbon-13 cross-polarization magic angle spinning nuclear magnetic resonance, scanning electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy were used to characterize the CCMPs. Then, CCMPs were used in CO 2 fixation and iodine vapor adsorption. The co-catalyst KI and CCMP-4 exhibited excellent activity in mild conditions, resulting in a 94% yield. The catalytic activity of the CCMP-4 was maintained after the five cycles. The kinetics of CCMP-4 was studied, and a potential reaction mechanism was proposed. The iodine adsorption experiments were conducted on CCMPs. The results showed that CCMPs exhibited excellent adsorption effects at 75 °C. The adsorption capacities of CCMP-1, CCMP-2, CCMP-3 and CCMP-4 were 3.02, 2.68, 2.72 and 3.21 g·g−1, respectively. The experimental results showed that CCMPs effectively absorbed iodine vapor and exhibited an excellent catalytic effect on CO 2 cycloaddition under mild conditions, which is proved by density functional theory calculations further. [Display omitted] • The CCMPs possessed high catalytic efficiency for cyclic carbonate. • The adsorption experiment of iodine vapor was carried out to evaluate the adsorption effect of polymers. • The synergistic mechanism has been proved in terms of experimental results, dynamics and DFT calculation. [ABSTRACT FROM AUTHOR]

• A crown ether functionalized PSf membrane was prepared by in situ graft on CMPSf membrane surface • The selective separation performance of for Li+ was improved membrane by coupling with electric field • The PSf-sg-AB12C4 dense membrane shows good selective separation for Li+. • The separation factor of the PSf-sg-AB12C4 dense membrane for Mg2+ to Li+ is up to 32.6. In order to improve the selective separation performance of the membrane for Li+ and enhance the separation efficiency, a crown ether functionalized polysulfone membrane was prepared in this paper, and the Li+ was separated by electrodialysis process. Chloromethylated polysulfone (CMPSf) was used as the base membrane, 4′-aminobenzo-12-crown-4-ether (AB12C4) was in-situ grafted onto the surface of CMPSf membrane to obtain the PSf-sg-AB12C4 membrane. The chemical structure of the membrane surface was characterized by ATR-FTIR and XPS. The surface and cross-sectional morphologies of the membrane were characterized by FESEM. The PSf-sg-AB12C4 membrane was used for selective separation of Li+ by membrane coupling with electric field. The results show that the CMPSf membranes and the PSf-sg-AB12C4 porous membrane have almost no selective separation performance for Li+, while the PSf-sg-AB12C4 dense membrane can selectively separate Li+. After optimizing the conditions of voltage, ion concentration and solution pH, the separation factor of the PSf-sg-AB12C4 dense membrane for Mg2+ to Li+ is up to 32.6. In addition, the separation factors of coexisting ions such as Na+, K +, Ca2+ to Li+ are all higher than that of Mg2+ to Li+, suggesting that the PSf-sg-AB12C4 dense membrane is a promising material for selective separation of Li+ from brine. [Display omitted] [ABSTRACT FROM AUTHOR]

• Efficient separation of actinides from HLW will help in nuclear waste management. • Separation of long-lived actinides from nuclear waste is extremely challenging. • TAM-3-DGA and TAM-4-DGA (multi-podal DGA) are promising ligands for actinides. • Use of RTILs in EXC enhanced the extraction efficiency of ligands several folds. • Two new EXC resins were prepared using TAM-3-DGA and TAM-4-DGA containing RTIL. Two new extraction chromatographic resins (ECRs) were prepared by impregnating two exotic diglycolamide (DGA) ligands (having three or four DGA moieties tethered to aza-crown ether scaffolds) dissolved in an ionic liquid onto an inert solid support. A room temperature ionic liquid (RTIL) was used for enhancing the performance of the ECRs. The ECR containing triaza-9-crown-3 functionalized with three DGA moieties (TAM-3-DGA), and tetraaza-12-crown-4 tethered with four DGA arms (TAM-4-DGA) were evaluated for the separation of Am3+ and Pu4+from nitric acid solutions. The resin capacity for Eu3+ was 9.52 mg/g and 7.24 mg/g for TAM-3-DGA and TAM-4-DGA resins, respectively. Similarly, the resin capacity for Pu4+was 7.44 mg/g and 5.72 mg/g for TAM-3-DGA and TAM-4-DGA resins, respectively. These maximum loading values corresponded to the formation of a 1:1 metal/ligand complex for the Eu3+ ion and a 1:2 metal/ligand complex for the Pu4+ ion. The sorption of Eu3+and Pu4+on the resins followed a chemisorption phenomenon on both resins. The sorbed Eu3+and Pu4+ions from the resin phase could be efficiently desorbed with complexing ligands such as guanidine carbonate/HEDTA and oxalic acid, respectively. [ABSTRACT FROM AUTHOR]

Adsorptive separation membranes are widely utilized for the removal of toxic dyeing pollutants from dyeing wastewater. However, developing novel adsorption membranes with large adsorption capacities and enhanced adsorption performance for dyes in actual wastewater poses a significant challenge. This study focuses on the fabrication of crown ether-containing copolymer porous membrane (CRPM) and investigation of the adsorption performance of dyes from aqueous solutions. The morphology structure and pore size distribution revealed that the membrane was endowed with rich micropores and hierarchical porous structures. Three typical cationic dyes (MB, RhB, CV) and an anionic dye (MO) were selected to evaluate the adsorption behavior. The results of adsorption isotherms and kinetics demonstrated that the adsorption data could be well-fitted using the Freundlich and pseudo-first-order kinetic models, the thermodynamic parameters revealed that the adsorption process of dyes on CRPM is a spontaneous endothermic reaction. The membrane exhibited excellent adsorption performance for cationic dyes, with RhB displaying a higher maximum adsorption capacity than previously reported porous membranes. Notably, dynamic adsorption-desorption filtration demonstrated a rapid removal efficiency, with RhB, MB, and CV achieving removal rates of 99.09%, 98.63%, and 99.14% respectively, after five cycles. The filtration volume of the CRPM membrane was 2.4-fold greater than that of a traditional PVDF membrane when applied to actual dyeing wastewater. DFT theoretical calculations were employed to elucidate the adsorption mechanism. These calculations confirmed the significant roles of electrostatic interactions, H-bonds and π–π interactions in facilitating the high-efficiency adsorption of cationic dyes. These findings highlight the potential of the crown ether-containing copolymer as a promising material for adsorption separation membranes in the treatment of dyeing wastewater. [Display omitted] • The membrane possessed abundant micropores and a hierarchical porous structure. • The membrane indicated significant enhanced adsorption performance for cationic dyes. • Dynamic adsorption-desorption achieved >99% removal of cationic dyes in five cycles. • The membrane exhibited a 2.4-fold volume increase vs. traditional PVDF in dyeing wastewater filtration. • DFT calculations highlight electrostatic attraction and H-bonds' vital role in enhancing adsorption. [ABSTRACT FROM AUTHOR]