-
ACS Macro Letters Mar 2022The developments of the living alkene polymerization method have achieved great progress and enabled the precise synthesis of important polyalkenes with controlled...
The developments of the living alkene polymerization method have achieved great progress and enabled the precise synthesis of important polyalkenes with controlled molecular weight, molecular weight distribution, and architecture through an anionic, cationic or radical strategy. However, it is still challenging to develop a living alkene polymerization method through an all-in-one strategy where anionic and radical characteristics are merged into one polymerization species. Here, a versatile living polymerization method is reported by introducing a well-established all-in-one covalent-anionic-radical Barbier strategy into a living polymerization. Through this living covalent-anionic-radical Barbier polymerization (Barbier CARP), narrow distributed polystyrenes, with as low as 1.05, are successfully prepared under mild conditions with a full monomer conversion by using wide varieties of organohalides, for example, alkyl, benzyl, allyl, and phenyl halides, as initiators with Mg in one pot. This living covalent-anionic-radical polymerization via a Barbier strategy expands the methodology library of polymer chemistry and enables living polymerization with an unconventional polymerization mode.
Topics: Alkenes; Anions; Molecular Weight; Polymerization; Polystyrenes
PubMed: 35575370
DOI: 10.1021/acsmacrolett.2c00010 -
Chemistry (Weinheim An Der Bergstrasse,... Aug 2021Synthetic anion transporters show much promise as potential anti-cancer agents and therapeutics for diseases associated with mis-regulation of protein anion channels. In...
Synthetic anion transporters show much promise as potential anti-cancer agents and therapeutics for diseases associated with mis-regulation of protein anion channels. In such applications high activity and anion selectivity are crucial to overcome competing proton or hydroxide transport which dissipates cellular pH gradients. Here, highly active bidentate halogen bonding and chalcogen bonding anion carriers based on electron deficient iodo- and telluromethyl-triazole derivatives are reported. Anion transport experiments in lipid bilayer vesicles reveal record nanomolar chloride transport activity for the bidentate halogen bonding anion carrier, and remarkably high chloride over proton/hydroxide selectivity for the chalcogen bonding anionophore. Computational studies provide further insight into the role of sigma-hole mediated anion recognition and desolvation at the membrane interface. Comparison with hydrogen bonding analogues demonstrates the importance of employing sigma-hole donor motifs in synthetic anionophores for achieving both high transport activity and selectivity.
Topics: Anions; Chalcogens; Chlorides; Halogens; Humans; Hydrogen Bonding
PubMed: 34014001
DOI: 10.1002/chem.202101681 -
ChemSusChem Apr 2022As highlighted by the recent roadmaps from the European Union and the United States, water electrolysis is the most valuable high-intensity technology for producing... (Review)
Review
As highlighted by the recent roadmaps from the European Union and the United States, water electrolysis is the most valuable high-intensity technology for producing green hydrogen. Currently, two commercial low-temperature water electrolyzer technologies exist: alkaline water electrolyzer (A-WE) and proton-exchange membrane water electrolyzer (PEM-WE). However, both have major drawbacks. A-WE shows low productivity and efficiency, while PEM-WE uses a significant amount of critical raw materials. Lately, the use of anion-exchange membrane water electrolyzers (AEM-WE) has been proposed to overcome the limitations of the current commercial systems. AEM-WE could become the cornerstone to achieve an intense, safe, and resilient green hydrogen production to fulfill the hydrogen targets to achieve the 2050 decarbonization goals. Here, the status of AEM-WE development is discussed, with a focus on the most critical aspects for research and highlighting the potential routes for overcoming the remaining issues. The Review closes with the future perspective on the AEM-WE research indicating the targets to be achieved.
Topics: Anions; Electrolysis; Hydrogen; Membranes, Artificial; Water
PubMed: 35263034
DOI: 10.1002/cssc.202200027 -
ELife Jul 2021Fluc family fluoride channels protect microbes against ambient environmental fluoride by undermining the cytoplasmic accumulation of this toxic halide. These proteins...
Fluc family fluoride channels protect microbes against ambient environmental fluoride by undermining the cytoplasmic accumulation of this toxic halide. These proteins are structurally idiosyncratic, and thus the permeation pathway and mechanism have no analogy in other known ion channels. Although fluoride-binding sites were identified in previous structural studies, it was not evident how these ions access aqueous solution, and the molecular determinants of anion recognition and selectivity have not been elucidated. Using x-ray crystallography, planar bilayer electrophysiology, and liposome-based assays, we identified additional binding sites along the permeation pathway. We used this information to develop an oriented system for planar lipid bilayer electrophysiology and observed anion block at one of these sites, revealing insights into the mechanism of anion recognition. We propose a permeation mechanism involving alternating occupancy of anion-binding sites that are fully assembled only as the substrate approaches.
Topics: Anions; Bacterial Proteins; Binding Sites; Biophysical Phenomena; Crystallography, X-Ray; Electrophysiology; Fluorides; Glutamic Acid; Ion Channels; Models, Molecular; Protein Conformation
PubMed: 34250906
DOI: 10.7554/eLife.69482 -
Nano Letters Jul 2022The free transport of anions in a Li metal battery can cause multiple issues, including a high anion transference number, space charge, and concentration polarization,...
The free transport of anions in a Li metal battery can cause multiple issues, including a high anion transference number, space charge, and concentration polarization, eventually leading to uncontrolled dendrite formation and decreased performance. Herein, we report an anion-anchoring nano-CaCO (NC) coating derived from eggshell biowaste for stabilizing Li metal anodes. As the adsorption of local TFSI anions onto the NC adsorbent can undermine the anion concentration gradient and promote rapid Li-ion diffusion, it can effectively inhibit the proliferation of Li dendrites assisted by the NC coating. Consequently, Li/Cu cells with NC@Cu electrode can achieve a high Coulombic efficiency of ∼98.4% for more than 420 cycles and can even reach ∼99.1% at an ultrahigh areal capacity of 20 mAh cm. In particular, full cells with NC/Li@Cu electrodes show a stable lifespan of over 240 cycles with an average efficiency of ∼99.8% at a low N/P ratio of ∼3.3.
Topics: Anions; Biomass; Ion Transport
PubMed: 35621512
DOI: 10.1021/acs.nanolett.2c01524 -
International Journal of Molecular... Jun 2022The synthesis and structural characterization of a series of supramolecular complexes of bicyclic cationic pyridine-fused 1,2,4-selenodiazoles with various anions is...
The synthesis and structural characterization of a series of supramolecular complexes of bicyclic cationic pyridine-fused 1,2,4-selenodiazoles with various anions is reported. The binding of trifluoroacetate, tetrachloroaurate, tetraphenylborate, perrhenate, and pertechnetate anions in the solid state is regarded. All the anions interact with selenodiazolium cations exclusively via a pair of "chelating" Se⋯O and H⋯O non-covalent interactions, which make them an attractive, novel, non-classical supramolecular recognition unit or a synthon. Trifluoroacetate salts were conveniently generated via novel oxidation reaction of 2,2'-dipyridyl diselenide with bis(trifluoroacetoxy)iodo)benzene in the presence of corresponding nitriles. Isolation and structural characterization of transient 2-pyridylselenyl trifluoroacetate was achieved. X-ray analysis has demonstrated that the latter forms dimers in the solid state featuring very short and strong Se⋯O and Se⋯N ChB contacts. 1,2,4-Selenodiazolium trifluoroacetates or halides show good solubility in water. In contrast, (AuCl), (ReO), or (TcO) derivatives immediately precipitate from aqueous solutions. Structural features of these supramolecular complexes in the solid state are discussed. The nature and energies of the non-covalent interactions in novel assembles were studied by the theoretical methods. To the best of our knowledge, this is the first study that regards perrhenate and pertechnetate as acceptors in ChB interactions. The results presented here will be useful for further developments in anion recognition and precipitation involving cationic 1,2,4-selenodiazoles.
Topics: Anions; Cations; Models, Theoretical; Salts; Sodium Pertechnetate Tc 99m; Trifluoroacetic Acid; Water
PubMed: 35742815
DOI: 10.3390/ijms23126372 -
Molecules (Basel, Switzerland) Jul 2019The discovery of the aggregation-induced emission (AIE) phenomenon in the early 2000s not only has overcome persistent challenges caused by traditional... (Review)
Review
The discovery of the aggregation-induced emission (AIE) phenomenon in the early 2000s not only has overcome persistent challenges caused by traditional aggregation-caused quenching (ACQ), but also has brought about new opportunities for the development of useful functional molecules. Through the years, AIE luminogens (AIEgens) have been widely studied for applications in the areas of biomedical and biological sensing, chemosensing, optoelectronics, and stimuli responsive materials. Particularly in the application of chemosensing, a myriad of novel AIE-based sensors has been developed to detect different neutral molecular, cationic and anionic species, with a rapid detection time, high sensitivity and high selectivity by monitoring fluorescence changes. This review thus summarises the recent development of AIE-based chemosensors for the detection of anionic species, including halides and halide-containing anions, cyanides, and sulphur-, phosphorus- and nitrogen- containing anions, as well as a few other anionic species, such as citrate, lactate and anionic surfactants.
Topics: Anions; Fluorescent Dyes; Halogens; Luminescent Measurements; Photochemical Processes
PubMed: 31349689
DOI: 10.3390/molecules24152711 -
Nanoscale Oct 2022Stimuli-responsive self-assembled and supramolecular hydrogels derived from peptide amphiphiles have opened exciting new avenues in biomedicine and drug delivery....
Stimuli-responsive self-assembled and supramolecular hydrogels derived from peptide amphiphiles have opened exciting new avenues in biomedicine and drug delivery. Herein, we screened a series of phenylalanine-amphiphiles possessing polyamine and oxyethylene appendages for their self-assembly and anion-responsiveness and found that the tris(aminoethyl)amine (TREN) containing amphiphile NapF-TREN formed injectable hydrogels that could be disrupted upon the addition of stoichiometric amounts of tetrahedral monovalent anions such as HPO and HSO, while the addition of other anions such as Cl, HPO, CO, HCO or SO did not affect the gel stability. The anion-gelator interaction was investigated by H and P NMR spectroscopy as well as by Isothermal Titration Calorimetry (ITC). These studies confirmed a 1 : 1 stoichiometry and revealed negative enthalpy and negative entropy for the binding of HPO with NapF-TREN. Microscopic investigations by TEM, AFM, and SAXS revealed that HPO anions induced a nanofiber-to-nanoglobule morphological change in the aqueous self-assemblies of NapF-TREN. However, upon ageing the samples, slow reformation of the nanofibers was also observed, reflecting the reversibility of the anion-gelator interaction. The anion- and pH-responsive nature of the NapF-TREN hydrogels was exploited to program sequential release of entrapped drugs propranolol and doxorubicin.
Topics: Hydrogels; Phenylalanine; Propranolol; Scattering, Small Angle; X-Ray Diffraction; Anions; Doxorubicin; Peptides; Polyamines
PubMed: 36200975
DOI: 10.1039/d2nr04320c -
Chemical Communications (Cambridge,... Mar 2022-Bambus[6]urils efficiently transport anions across lipid membranes. A systematic modification of their lipophilic side chains to include various alkyl groups and...
-Bambus[6]urils efficiently transport anions across lipid membranes. A systematic modification of their lipophilic side chains to include various alkyl groups and thioethers reveals that the most efficient chloride transporters are those that agree with Lipinski's rule-of-lipophilicity, exhibiting clog values close to 5. Furthermore, vesicle anion-transport assays show that the new anion-transporters are independent of the cation identity but exhibit high anion selectivity, NO > Br > Cl > SO, in agreement with the Hofmeister series. These findings will allow for the design of highly specific anion transporters for biomedical applications, particularly for managing anion channelopathies.
Topics: Anions; Biological Transport; Crystallography, X-Ray; Models, Molecular; Molecular Structure; Organic Anion Transporters; Urine
PubMed: 35170624
DOI: 10.1039/d2cc00144f -
ACS Sensors Aug 2023We report here a small library of a new type of acyclic squaramide receptors (-) as selective ionophores for the detection of ketoprofen and naproxen anions (KF and NS,...
We report here a small library of a new type of acyclic squaramide receptors (-) as selective ionophores for the detection of ketoprofen and naproxen anions (KF and NS, respectively) in aqueous media. H NMR binding studies show a high affinity of these squaramide receptors toward KF and NS, suggesting the formation of H-bonds between the two guests and the receptors through indole and -NH groups. Compounds - have been tested as ionophores for the detection of KF and NS inside solvent PVC-based polymeric membranes. The optimal membrane compositions were established through the careful variation of the ligand/tridodecylmethylammonium chloride (TDMACl) anion-exchanger ratio. All of the tested acyclic squaramide receptors - have high affinity toward KF and NS and anti-Hofmeister selectivity, with and showing the highest sensitivity and selectivity to NS. The utility of the developed sensors for a high precision detection of KF in pharmaceutical compositions with low relative errors of analysis (RSD, 0.99-1.4%) and recoveries, %, in the range 95.1-111.8% has been demonstrated. Additionally, the chemometric approach has been involved to effectively discriminate between the structurally very similar KF and NS, and the possibility of detecting these analytes at concentrations as low as 0.07 μM with of 0.947 and at 0.15 μM with of 0.919 for NS and KF, respectively, was shown.
Topics: Ionophores; Anions; Quinine
PubMed: 37530141
DOI: 10.1021/acssensors.3c00981