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ChemPlusChem Nov 2022Anion templated assembly of supramolecular systems has been extensively explored in previous reports, whereas anions serve only as an auxiliary and spectator role. With... (Review)
Review
Anion templated assembly of supramolecular systems has been extensively explored in previous reports, whereas anions serve only as an auxiliary and spectator role. With the development of anion coordination chemistry in recent years, anion coordination-driven assembly (ACDA) has emerged as a new strategy for the construction of supramolecular self-assemblies. Anions are proved to exist as the main actors in the construction of supramolecular architectures, i. e., serve as the coordination center. This Review will focus on the recent progress in anion-coordination-driven assembly of discrete supramolecular architectures, such as helicates, polyhedrons and polygons, and the various applications of 'aniono'-systems. At the end of this Review, we highlight current challenges and opportunities for future research of anion-coordination-driven self-assembly.
Topics: Anions
PubMed: 36410745
DOI: 10.1002/cplu.202200294 -
Organic & Biomolecular Chemistry Jul 2023The synthesis, acid-base behaviour and anion recognition of neurotransmitters (dopamine, tyramine and serotonin) in aqueous solution of different aza-scorpiand ligands...
The synthesis, acid-base behaviour and anion recognition of neurotransmitters (dopamine, tyramine and serotonin) in aqueous solution of different aza-scorpiand ligands functionalized with hydroxyphenyl and phenyl moieties (L1-L3 and L4, respectively) have been studied by potentiometry, NMR, UV-Vis and fluorescence spectroscopy and isothermal titration calorimetry (ITC). The analysis of the potentiometric results shows the selective recognition of serotonin at physiological pH ( = 8.64 × 10) by L1. This selectivity has an entropic origin probably coming from a fine pre-organization of the interacting partners. Thus, the complementarity of the receptor and the substrate allows the reciprocal formation of hydrogen bonds, π-π and cation-π interactions, stabilizing the receptors and slowing the rate of oxidative degradation, and satisfactory results are obtained at acidic and neutral pH values. NMR and molecular dynamics studies reveal the rotation blockage in the neurotransmitter side chain once complexed with L1.
Topics: Ligands; Serotonin; Water; Anions; Oxidation-Reduction
PubMed: 37335019
DOI: 10.1039/d3ob00562c -
The Journal of Organic Chemistry Jan 2022A series of triazole-cyanostilbene receptors were designed and synthesized. The receptor binds with the anions through various CH···anion hydrogen bonding...
A series of triazole-cyanostilbene receptors were designed and synthesized. The receptor binds with the anions through various CH···anion hydrogen bonding interactions, where strong binding was observed for SO anions followed by Cl, Br, NO, and I, calculated from the H NMR titration experiment. The NOESY NMR experiment of the receptor confirmed the formation of anion-induced folded conformation. The CH···anion hydrogen bonding interaction-mediated anion recognition and foldamer formation were further confirmed from geometry optimization studies of the anion-bound complex. The receptor transports Cl anions efficiently compared to SO anions across the lipid bilayer membrane via a mobile carrier mechanism.
Topics: Anions; Hydrogen; Hydrogen Bonding; Molecular Conformation; Phospholipids
PubMed: 34908424
DOI: 10.1021/acs.joc.1c01408 -
Dalton Transactions (Cambridge, England... Sep 2022Ion pair receptors typically contain two separate binding sites, for the metal and the anion respectively. Here we report a less synthetically demanding approach,...
Ion pair receptors typically contain two separate binding sites, for the metal and the anion respectively. Here we report a less synthetically demanding approach, whereby we prepared a family of ion pair sensors based on a rhodamine fluorescent scaffold containing a tunable cation binding motif. When exposed to ion pairs, a competition for the metal ion is established between these ligands and anions. Structural and spectroscopic evidence showed that anions bind through weaker secondary interactions in the metal's outer coordination sphere and their presence influences the optical spectroscopic properties of the coordination complex in distinctive ways. The relationship between the binding site's metal affinity and its tunable properties, and the sensors' discriminatory power for anions was explained as a function of the metal ion's binding preferences. These effects were also exploited to discriminate cations and anions concurrently through multivariate data analysis methods.
Topics: Anions; Cations; Ligands; Metals; Rhodamines
PubMed: 35975743
DOI: 10.1039/d2dt01794f -
Chemistry (Weinheim An Der Bergstrasse,... Dec 2022The synthesis and characterisation of a library of acyclic antimony(III) and bismuth(III) triaryl pnictogen bonding (PnB) receptor systems are reported. In the...
The synthesis and characterisation of a library of acyclic antimony(III) and bismuth(III) triaryl pnictogen bonding (PnB) receptor systems are reported. In the first-generation receptor series, quantitative H NMR chloride titration experiments in THF solvent media reveal halide anion binding potency is intimately correlated with both the electronic-withdrawing nature of the aryl- substituent and the polarisability of the PnB donor. Further extensive anion binding investigations with the most potent Sb- and Bi-based PnB receptors: 1⋅Sb and 1⋅Bi , reveal novel selectivity profiles, both displaying Cl selectivity relative to the heavier halides and, impressively, to a range of highly basic oxoanions. The synthesis and preliminary chloride anion binding studies of a series of novel tripodal tris-proto-triazole triaryl Sb(III) and Bi(III) mixed PnB-HB receptor systems are also described. Whereas parent triphenyl Sb(III) and Bi(III) compounds are incapable of binding Cl in THF solvent media, the PnB-triazole HB host systems exhibit notable halide affinity.
Topics: Antimony; Bismuth; Chlorides; Anions; Halogens; Triazoles; Solvents
PubMed: 35968660
DOI: 10.1002/chem.202201838 -
Chemphyschem : a European Journal of... Jan 2023Modulation and fine-tuning of the strength of weak interactions to bind anions are described in a series of synthetic receptors. The general design of the receptors...
Modulation and fine-tuning of the strength of weak interactions to bind anions are described in a series of synthetic receptors. The general design of the receptors includes both a urea motif and a tetrazine motif. The synthetic sequence towards three receptors is detailed. Impacts of H-bond strength and linker length between urea and tetrazine on chloride complexation are studied. Binding properties of the chloride anion are examined in both the ground and excited states using a panel of analytical methods (NMR spectroscopy, mass spectrometry, UV/Visible spectroscopies, and fluorescence). A ranking of the receptors by complexation strength has been determined, allowing a better understanding of the structure-properties relationship on these compounds.
Topics: Urea; Chlorides; Hydrogen Bonding; Anions
PubMed: 36111796
DOI: 10.1002/cphc.202200524 -
Journal of Computational Chemistry Sep 2022The ion association is widely believed to be dominated by the favorable entropy change arising from the release of water molecules from ion hydration shells. However, no...
The ion association is widely believed to be dominated by the favorable entropy change arising from the release of water molecules from ion hydration shells. However, no direct thermodynamic evidence exists to validate the reliability and suitability of this view. Herein, we employ complicated free energy calculations to rigorously split the free energy including its entropic and enthalpic components into the water-induced contributions and ion-ion interaction terms for several ion pairs from monatomic to polyatomic ions, spanning the size range from small kosmotropes to large chaotropes (Na , Cs , Ca , F , I , CO , and HPO ). Our results successfully reveal that though ion associations are indeed determined by a delicate balance between the favorable entropy variation and the repulsive enthalpy change, the entropy gain dominated by the solvent occurs only for the monatomic ion pairing. The water-induced entropic contribution significantly goes against the ion pairing between polyatomic anion and cation, which is, alternatively, dominated by the favorable entropy from the ion-ion interaction term, due to the configurational arrangement of polyatomic anions involved in ion association. The structural and dynamic analysis demonstrates that the entropy penalty from the water phase is primarily ascribed to the enhanced stability of water molecules around the cation imposed by the incoming anion. Our study successfully provides a fundamental understanding of water-mediated ion associations and highlights disparate lengthscale dependencies of the dehydration thermodynamics on the specific types of ions.
Topics: Anions; Cations; Entropy; Reproducibility of Results; Thermodynamics; Water
PubMed: 35801676
DOI: 10.1002/jcc.26963 -
Journal of the American Chemical Society Jan 2023When high-energy radiation passes through aqueous material, low-energy electrons are produced which cause DNA damage. Electronic states of anionic nucleobases have been...
When high-energy radiation passes through aqueous material, low-energy electrons are produced which cause DNA damage. Electronic states of anionic nucleobases have been suggested as an entrance channel to capture the electron. However, identifying these electronic resonances have been restricted to gas-phase electron-nucleobase studies and offer limited insight into the resonances available within the aqueous environment of DNA. Here, resonance and detachment energies of the micro-hydrated uracil pyrimidine nucleobase anion are determined by two-dimensional photoelectron spectroscopy and are shown to extrapolate linearly with cluster size. This extrapolation allows the corresponding resonance and detachment energies to be determined for uracil in aqueous solution as well as the reorganization energy associated with electron capture. Two shape resonances are clearly identified that can capture low-energy electrons and subsequently form the radical anion by solvent stabilization and internal conversion to the ground electronic state. The resonances and their dynamics probed here are the nucleobase-centered doorway states for low-energy electron capture and damage in DNA.
Topics: Water; Uracil; Anions; Solvents; DNA
PubMed: 36584340
DOI: 10.1021/jacs.2c11440 -
Molecules (Basel, Switzerland) Jun 2020Polyhydroborate salts represent the important class of energy materials attracting significant recent attention. Some of these salts exhibit promising hydrogen storage... (Review)
Review
Polyhydroborate salts represent the important class of energy materials attracting significant recent attention. Some of these salts exhibit promising hydrogen storage properties and/or high ionic conductivities favorable for applications as solid electrolytes in batteries. Two basic types of thermally activated atomic jump motion are known to exist in these materials: the reorientational (rotational) motion of complex anions and the translational diffusion of cations or complex anions. The present paper reviews recent progress in nuclear magnetic resonance (NMR) studies of both reorientational and diffusive jump motion in polyhydroborate salts. The emphasis is put on sodium and lithium -borates exhibiting high ionic conductivity and on borohydride-based systems showing extremely fast reorientational motion down to low temperatures. For these systems, we discuss the effects of order-disorder phase transitions on the parameters of reorientations and diffusive jumps, as well as the mechanism of low-temperature rotational tunneling.
Topics: Anions; Bromates; Cations; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Conformation; Salts
PubMed: 32604750
DOI: 10.3390/molecules25122940 -
Molecules (Basel, Switzerland) Feb 2021Biodegradable and antimicrobial waterborne polyurethane dispersions (PUDs) and their casted solid films have recently emerged as important alternatives to their... (Review)
Review
Biodegradable and antimicrobial waterborne polyurethane dispersions (PUDs) and their casted solid films have recently emerged as important alternatives to their solvent-based and non-biodegradable counterparts for various applications due to their versatility, health, and environmental friendliness. The nanoscale morphology of the PUDs, dispersion stability, and the thermomechanical properties of the solid films obtained from the solvent cast process are strongly dependent on several important parameters, such as the preparation method, polyols, diisocyanates, solid content, chain extension, and temperature. The biodegradability, biocompatibility, antimicrobial properties and biomedical applications can be tailored based on the nature of the polyols, polarity, as well as structure and concentration of the internal surfactants (anionic or cationic). This review article provides an important quantitative experimental basis and structure evolution for the development and synthesis of biodegradable waterborne PUDs and their solid films, with prescribed macromolecular properties and new functions, with the aim of understanding the relationships between polymer structure, properties, and performance. The review article will also summarize the important variables that control the thermomechanical properties and biodegradation kinetics, as well as antimicrobial and biocompatibility behaviors of aqueous PUDs and their films, for certain industrial and biomedical applications.
Topics: Anions; Anti-Infective Agents; Biodegradable Plastics; Humans; Polymers; Polyurethanes; Solvents; Surface-Active Agents; Water
PubMed: 33670378
DOI: 10.3390/molecules26040961