Ionic liquid cations as methylation agent for extremely weak chalcogenido metalate nucleophiles.
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ABSTRACT:
SUBMITTER: Peters B
PROVIDER: S-EPMC6540918 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Room temperature ionic liquids (RTILs) are solvent-free liquids comprised of densely packed cations and anions. The low vapor pressure and low flammability make ILs interesting for electrolytes in batteries. In this work, a new class of ionic liquids were formed for rechargeable aluminum/graphite battery electrolytes by mixing 1-methyl-1-propylpyrrolidinium chloride (Py13Cl) with various ratios of aluminum chloride (AlCl3) (AlCl3/Py13Cl molar ratio = 1.4 to 1.7). Fundamental properties of the ionic liquids, including density, viscosity, conductivity, anion concentrations and electrolyte ion percent were investigated and compared with the previously investigated 1-ethyl-3-methylimidazolium chloride (EMIC-AlCl3) ionic liquids. The results showed that the Py13Cl-AlCl3 ionic liquid exhibited lower density, higher viscosity and lower conductivity than its EMIC-AlCl3 counterpart. We devised a Raman scattering spectroscopy method probing ILs over a Si substrate, and by using the Si Raman scattering peak for normalization, we quantified speciation including AlCl4 -, Al2Cl7 -, and larger AlCl3 related species with the general formula (AlCl3) n in different IL electrolytes. We found that larger (AlCl3) n species existed only in the Py13Cl-AlCl3 system. We propose that the larger cationic size of Py13+ (142 Å3) versus EMI+ (118 Å3) dictated the differences in the chemical and physical properties of the two ionic liquids. Both ionic liquids were used as electrolytes for aluminum-graphite batteries, with the performances of batteries compared. The chloroaluminate anion-graphite charging capacity and cycling stability of the two batteries were similar. The Py13Cl-AlCl3 based battery showed a slightly larger overpotential than EMIC-AlCl3, leading to lower energy efficiency resulting from higher viscosity and lower conductivity. The results here provide fundamental insights into ionic liquid electrolyte design for optimal battery performance.
| S-EPMC9062991 | biostudies-literature
Project description:Ionic liquids (ILs) are known for their unique characteristics as solvents and electrolytes. Therefore, new ILs are being developed and adapted as innovative chemical environments for different applications in which their properties need to be understood on a molecular level. Computational data-driven methods provide means for understanding of properties at molecular level, and quantitative structure-property relationships (QSPRs) provide the framework for this. This framework is commonly used to study the properties of molecules in ILs as an environment. The opposite situation where the property is considered as a function of the ionic liquid does not exist. The aim of the present study was to supplement this perspective with new knowledge and to develop QSPRs that would allow the understanding of molecular interactions in ionic liquids based on the structure of the cationic moiety. A wide range of applications in electrochemistry, separation and extraction chemistry depends on the partitioning of solutes between the ionic liquid and the surrounding environment that is characterized by the gas-ionic liquid partition coefficient. To model this property as a function of the structure of a cationic counterpart, a series of ionic liquids was selected with a common bis-(trifluoromethylsulfonyl)-imide anion, [Tf2N]-, for benzene, hexane and cyclohexane. MLR, SVR and GPR machine learning approaches were used to derive data-driven models and their performance was compared. The cross-validation coefficients of determination in the range 0.71-0.93 along with other performance statistics indicated a strong accuracy of models for all data series and machine learning methods. The analysis and interpretation of descriptors revealed that generally higher lipophilicity and dispersion interaction capability, and lower polarity in the cations induces a higher partition coefficient for benzene, hexane, cyclohexane and hydrocarbons in general. The applicability domain analysis of models concluded that there were no highly influential outliers and the models are applicable to a wide selection of cation families with variable size, polarity and aliphatic or aromatic nature.
| S-EPMC9323540 | biostudies-literature
Project description:ConspectusDiscovering and constructing molecular functionality platforms for materials chemistry innovation has been a persistent target in the fields of chemistry, materials, and engineering. Around this task, basic scientific questions can be asked, novel functional materials can be synthesized, and efficient system functionality can be established. Poly(ionic liquid)s (PILs) have attracted growing interest far beyond polymer science and are now considered an interdisciplinary crossing point between multiple research areas due to their designable chemical structure, intriguing physicochemical properties, and broad and diverse applications. Recently, we discovered that 1,2,4-triazolium-type PILs show enhanced performance profiles, which are due to stronger and more abundant supramolecular interactions ranging from hydrogen bonding to metal coordination, when compared with structurally similar imidazolium counterparts. This phenomenon in our view can be related to the smart hydrogen atoms (SHAs), that is, any proton that binds to the carbon in the N-heterocyclic cations of 1,2,4-triazolium-type PILs. The replacement of one carbon by an electron-withdrawing nitrogen atom in the broadly studied heterocyclic imidazolium ring will further polarize the C-H bond (especially for C5-H) of the resultant 1,2,4-triazolium cation and establish new chemical tools for materials design. For instance, the H-bond-donating strength of the SHA, as well as its Bro̷nsted acidity, is increased. Furthermore, polycarbene complexes can be readily formed even in the presence of weak or medium bases, which is by contrast rather challenging for imidazolium-type PILs. The combination of SHAs with the intrinsic features of heterocyclic cation-functionalized PILs (e.g., N-coordination capability and polymeric multibinding effects) enables new phenomena and therefore innovative materials applications.In this Account, recent progress on SHAs is presented. SHA-related applications in several research branches are highlighted together with the corresponding materials design at size scales ranging from nano- to micro- and macroscopic levels. At a nanoscopic level, it is possible to manipulate the interior and outer shapes and surface properties of PIL nanocolloids by adjusting the hydrogen bonds (H-bonds) between SHAs and water. Owing to the interplay of polycarbene structure, N-coordination, and the polymer multidentate binding of 1,2,4-triazolium-type PILs, metal clusters with controllable size at sub-nanometer scale were successfully synthesized and stabilized, which exhibited record-high catalytic performance in H2 generation via methanolysis of ammonia borane. At the microscopic level, SHAs are found to efficiently catalyze single crystal formation of structurally complex organics. Free protons in situ released from the SHAs serve as organocatalysts to activate formation of C-N bonds at room temperature in a series of imine-linked crystalline porous organics, such as organic cages, macrocycles and covalent organic frameworks; meanwhile the concurrent "salting-out" effect of PILs as polymers in solution accelerated the crystallization rate of product molecules by at least 1 order of magnitude. At the macroscopic scale, by finely regulating the supramolecular interactions of SHAs, a series of functional supramolecular porous polyelectrolyte membranes (SPPMs) with switchable pores and gradient cross-sectional structures were manufactured. These membranes demonstrate impressive figures of merit, ranging from chiral separation and proton recognition to switchable optical properties and real-time chemical reaction monitoring. Although the concept of SHAs is in the incipient stage of development, our successful examples of applications portend bright prospects for materials chemistry innovation.
| S-EPMC9774662 | biostudies-literature
Project description:We used AML12 cells exposured with pulsed extremely low frequency weak magnetic fields for 4 msec at increasing frequency of 1, 2, 3, 4, 5, 6, 7, and 8 Hz for 1 sec each. The 1-to-8 Hz pulses over 8 sec were repeated indefinitely. Peak magnetic intensity was 100 mG. AML12 cells were incubated for 1 h under extremely low frequency weak magnetic fields.
2022-05-05 | GSE166811 | GEO
Project description:Supertetrahedral clusters have been reported in two generally different types so far: one type possessing an organic ligand shell, no or low charges, and high solubility, while the other cluster type is ligand-free with usually high charges and low or no solubility in common solvents. The latter is a tremendous disadvantage regarding further use of the clusters in solution. However, as organic substituents usually broaden the HOMO-LUMO gaps, which cannot be overcompensated by the (limited) cluster sizes, a full organic shielding comes along with drawbacks regarding opto-electronic properties. We therefore sought to find a way of generating soluble clusters with a minimum number of organic substituents. Here, we present the synthesis and full characterization of two salts of [Sn10 O4 S16 (SBu)4 ]4- that are high soluble in CH2 Cl2 or CH3 CN, which includes first NMR and mass spectra obtained from solutions of such salts with mostly inorganic supertetrahedral clusters. The optical absorption properties of this new class of compounds indicates nearly unaffected band gaps. The synthetic approach and the spectroscopic findings were rationalized and explained by means of high-level quantum chemical studies.
| S-EPMC8362043 | biostudies-literature
Project description:Carbon dioxide, as a promising C1 synthon, has attracted great interest in organic synthesis. Due to the thermodynamic stability and kinetic inertness of CO2, developing efficient strategies for CO2 activation and subsequent conversion is very crucial. In this context, Ionic liquids (ILs) show great potential for capturing and activating CO2 owing to their unique structures and properties, making them become ideal alternatives to volatile organic solvents and/or catalysts for CO2 transformation. This minireview aims at summarizing ILs-promoted reactions of CO2 with N-nucleophiles (primary amines)/O-nucleophiles (primary alcohols, water). Two catalytic systems i.e., metal/ILs binary systems such as Cu/ILs systems and Ag/ILs systems as well as single ILs systems including anion-functionalized ILs and bifunctionalized ILs have been developed for CO2 catalytic conversion, for instance, carboxylative cyclization of nucleophiles e.g., propargylic alcohols, amines, 2-aminobenzonitriles and o-aminobenzenethiol, and formylation of amines or 2-aminothiophenols with hydrosilanes to afford various value-added chemicals e.g., cyclic carbamates, unsymmetrical organic carbonates, ?-hydroxyl ketones, and benzimidazolones. In a word, IL could provide a powerful tool for efficient CO2 utilization.
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Project description:Forward osmosis (FO) has emerged as a new technology for desalination and exhibits potentials for applications where reverse osmosis is incapable or uneconomical for treating streams with high salinity or fouling propensity. However, most of current draw agents in FO are salts and difficult to be recycled cost- and energy-effectively. In this work, we demonstrate a new and facile approach to efficiently recover water from the FO process with enhanced water purity by using a binary ion liquid/hydrogel system. The hybrid ion liquid/hydrogel draw solution system demonstrated in this work synergistically leverages the thermoresponsive properties of both the ionic liquid (IL) and hydrogel to improve the overall FO performance. Our findings corroborate that the hydrogel mitigates the water flux decline of the IL as the draw agent and provide a ready route to contiguously and effectively regenerate water from the FO process. Such a route allows for an efficient recovery of water from the draw solute/water mixture with enhanced water purity, compared with conventional thermal treating of lower critical solution temperature IL draw solute/water. Furthermore, hydrogels can be used in a continuous and readily recyclable process to recover water without heating the entire draw solute/water mixture. Our design principles open the door to use low-grade/waste heat or solar energy to regenerate draw agents and potentially reduce energy in the FO process considerably.
| S-EPMC6648795 | biostudies-literature
Project description:Pancreatic ductal adenocarcinoma rapidly acquires resistance to chemotherapy, remaining a fatal disease. Immunotherapy is one of the breakthroughs in cancer treatment, which includes immune checkpoint inhibitors, chimeric antigen receptor T-cell immunotherapy, and neoantigen vaccines. However, immunotherapy has not achieved satisfactory results in the treatment of pancreatic cancer. Immunogenic death comprises proinflammatory cell death, which provides a way to enhance tumor immunogenicity and promote an immune response in solid tumors. Herein, an ionic liquid ablation agent (LAA), synthesized from choline and geranic acid, which triggers necrosis-induced immunotherapy by remodeling an immunosuppressive "cold" tumor to an immune activated "hot" tumor is described. The results indicate that LAA-treated tumor cells can enhance immunogenicity, inducing dendritic cell maturation, macrophage M1 polarization, and cytotoxic T lymphocyte infiltration. The results of the present study provide a novel strategy for solid tumor immunotherapy.
| S-EPMC10074093 | biostudies-literature
Project description:1-N-Butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF6], and its methylated form, 1-N-butyl-2,3-dimethylimidazolium hexafluorophosphate, [BMMIM][PF6], were incorporated into CuBTC to examine the effect of methylation of ionic liquids (ILs) on the gas separation performance of the corresponding IL/metal-organic framework (MOF) composites. Spectroscopic analysis revealed that the interactions of the methylated ILs with CuBTC were weaker compared to those of its non-methylated counterpart. Gas uptake measurements illustrated that this difference in the interactions influences the gas separation performance of the composites. Accordingly, the CO2/N2: 15/85 and CH4/N2: 50/50 selectivities increased by 37% and 60% for [BMMIM][PF6]/CuBTC and 34% and 50% for [BMIM][PF6]/CuBTC, respectively, compared to the corresponding selectivities of pristine CuBTC at 1000 mbar. The results revealed another structural parameter controlling the performance of the IL/MOF composites, a novel type of material with rapidly expanding application areas.
| S-EPMC6333260 | biostudies-literature
Project description:As the dysprosocenium complex [Dy(Cpttt )2 ][B(C6 F5 )4 ] (Cpttt =C5 H2 tBu3 -1,2,4, 1-Dy) exhibits magnetic hysteresis at 60 K, similar lanthanide (Ln) complexes have been targeted to provide insights into this remarkable property. We recently reported homologous [Ln(Cpttt )2 ][B(C6 F5 )4 ] (1-Ln) for all the heavier Ln from Gd-Lu; herein, we extend this motif to the early Ln. We find, for the largest LnIII cations, that contact ion pairs [Ln(Cpttt )2 {(C6 F5 -κ1 -F)B(C6 F5 )3 }] (1-Ln; La-Nd) are isolated from reactions of parent [Ln(Cpttt )2 (Cl)] (2-Ln) with [H(SiEt3 )2 ][B(C6 F5 )4 ], where the anion binds weakly to the equatorial sites of [Ln(Cpttt )2 ]+ through a single fluorine atom in the solid state. For smaller SmIII , [Sm(Cpttt )2 ][B(C6 F5 )4 ] (1-Sm) is isolated, which like heavier 1-Ln does not exhibit equatorial anion interactions, but the EuIII analogue 1-Eu could not be synthesised due to the facile reduction of EuIII precursors to EuII products. Thus with the exception of Eu and radioactive Pm this work constitutes a structurally similar family of Ln metallocenium complexes, over 50 years after the [M(Cp)2 ]+ series was isolated for the 3d metals.
| S-EPMC6637382 | biostudies-literature