Selective Solid–Liquid and Liquid–Liquid Extraction of Lithium Chloride Using Strapped Calix[4]pyrroles

LiCl is a classic “hard” ion salt that is present in lithium‐rich brines and a key component in end‐of‐life materials (that is, used lithium‐ion batteries). Its isolation and purification from like salts is a recognized challenge with potential strategic and economic implications. Herein, we describe two ditopic calix[4]pyrrole‐based ion‐pair receptors ( 2 and 3 ), that are capable of selectively capturing LiCl. Under solid–liquid extraction conditions, using 2 as the extractant, LiCl could be separated from a NaCl/KCl salt mixture containing as little as 1 % LiCl with circa 100 % selectivity, while receptor 3 achieved similar separations when the LiCl level was as low as 200 ppm. Under liquid–liquid extraction conditions using nitrobenzene as the non‐aqueous phase, the extraction preference displayed by 2 is KCl>NaCl>LiCl. In contrast, 3 exhibits high selectivity towards LiCl over NaCl and KCl, with no appreciable extraction being observed for the latter two salts.     

Transport of alkali halides through a liquid organic membrane containing a ditopic salt-binding receptor

A ditopic receptor is shown to have an impressive ability to recognize and extract the ion pairs of various alkali halides into organic solution. X-ray diffraction analysis indicates that the salts are bound in the solid state as contact ion pairs. Transport experiments, using a supported liquid membrane and high salt concentration in the source phase, show that the ditopic receptor can transport alkali halide salts up to 10-fold faster than a monotopic cation or anion receptor and 2-fold faster than a binary mixture of cation and anion receptors. All transport systems exhibit the same qualitative order of ion selectivity; that is, for a constant anion, the cation selectivity order is K+ > Na+ > Li+, and for a constant cation, the anion transport selectivity order is I- > Br- > Cl-. The data suggest that with a ditopic receptor, the polarity of the receptor-salt complex can be lowered if the salt is bound as an associated ion pair, which leads to a faster diffusion through the membrane and a higher maximal flux.     

在盐的水溶液中非电解质活度系数的研究(Ⅺ)——正丙酸和正丁酸在苯和盐水溶液间的分配

在25℃下分别测定正丙酸和正丁酸在苯相和纯水相中的分配比,以及在苯相和盐水溶液中的分配比,从而求出酸的活度系数。所用的盐有氯化锂、氯化钠、氯化钾、氯化锶、氯化钡、溴化锂、溴化钠、溴化钾等八种。对弱酸算出了未解离部分的活度系数。在所用盐浓度(0-1mol/l)范围内,作lgf_u-C_s图,都呈直线。比较直线的斜率,对正丙酸为:SrCl₂>BaCl₂>LiCl≈NaCl>LiBr≈NaBr>KCl>KBr。对正了酸为:SrCl₂>BaCl₂>NaCl≈LiC₁>NaBr≈KCl≈LiBr>KBr.指出小离子盐对小脂肪酸盐效应主要是静电力作用。     

Effect of electrolytes on the cloud point of chlorpromazine hydrochloride solutions

Cloud point (CP) phenomenon occurring in amphiphilic drug chlorpromazine hydrochloride (CPZ) solutions with and without salts is reported herein. The CP of a 50mM CPZ solution (prepared in 10mM sodium phosphate, SP, buffer) was found to decrease with increasing pH, both in the absence as well as presence (50mM) of added salts (NaCl, NaBr, LiBr, KBr, tetra-n-butylammonium bromide). Whereas, at a fixed concentration of NaCl, the CP increased with increasing CPZ concentration, addition of increasing amounts of salts (NaF, NaCl, NaBr, LiCl, KCl) to 50mM CPZ solution (at pH 6.7) caused continuous increase in CP. On the basis of these studies the binding-effect orders of counterions and co-ions have been deduced, respectively, as: Br(-)>Cl(-)>F(-) and Li(+)>Na(+)>K(+). The similar trend of increasing CP with addition of increasing amounts of quaternary bromides (tetramethylammonium bromide, TMeAB; tetraethylammonium bromide, TEtAB; tetra-n-propylammonium bromide, TPrAB; tetra-n-butylammonium bromide, TBuAB; tetra-n-pentylammonium bromide, TPeAB) to 50mM CPZ solutions (at pH 6.7) was found to be dependent upon the alkyl chain length of the particular salt. The overall behaviour has been discussed in terms of electrostatic interactions, micellar growth, and mixed micelle formation.     

Ab initio computation of low-temperature phase diagrams exhibiting miscibility gaps

A new methodology for the computation of the low-temperature part of phase diagrams without recourse to any experimental information is presented. A central element is a procedure for deciding whether formation of crystalline solid solution phases can take place in the chemical system. Via global exploration of the enthalpy landscapes for many different compositions in the system, candidates for ordered stoichiometric and crystalline solid solution phases are identified. Next, their free enthalpies are computed at ab initio level and a low-temperature phase diagram is derived. As examples, the low-temperature phase diagrams for the ternary alkali halides NaCl/LiCl NaBr/LiBr and NaCl/KCl are presented.     

ChemInform Abstract: Electron Affinities of the Alkali Halides and the Structure of Their Negative Ions.

The electron affinities obtained from the photoelectron spectra of ten MX^- anions (488 nm) increase with the mass of halogen and decrease with increasing mass of the alkali metal: NaF:0.520, NaCl:0.727, NaBr:0.788, NaI:0.865, KCl:0.582, KBr:0.642, KI:0.728, LiCl:0.593, RbCl:0.543, and CsCl:0.455 eV.     

Transference Numbers and Activity Coefficients of Some Alkali Metal Halide Solutions in Ethylene Glycol,Using Concentration Cells

Abstract

The reliability of the concentration cell method for determining cation transference numbers has been tested using solutions of LiCl, NaCl, KCl, NaBr and LiBr in ethylene glycol at 25°C. Concentrations in the range 0.0005 to 0.5 mol dm^?3 were used. Our transference numbers have been compared with those deduced from previous data on moving boundary and conductivity experiments. Good agreement between both sets of values has been found in most of the solutions, but significant discrepancies appear in the cases of NaBr and LiCl. The mean activity coefficients have been calculated from the EMF data and the transference numbers.     

邻、间、对位-二甲苯在盐的水溶液中活度系数的研究

本文用紫外分光光度计测定了25 ℃下邻、间、对位三种二甲苯在八种盐水溶液中的活度系数f和盐析常数k值。所用的盐为LiCl、NaCl、KCl、SrCl2、BaCl2、LiBr、NaBr、KBr。将三种二甲苯的lgf分别对八种盐的浓度C_s作图, 得到二十四条通过原点的直线, 符合Setschenow盐析经验公式。三种二甲苯的盐析次序均为BaCl2>SrCl_2>NaCl>KCl>NaBr≈LiCl>KBr>LiBr.实验表明: 每种盐的盐效应是单个离子的贡献之和; 随着二甲苯偶极矩的增大, 盐析常数有下降的趋势。本文计算了四种理论的盐析常数k_s值。对内压力理论改进公式提出了一些假设, 选用了Latimer离子半径进行具体计算, 结果与实验值符合得较好.对于体积较大的非电解质, 虽然静电力起主要作用, 但必须考虑色散力对盐析常数的影响。本文再一次证实和支持了黄子卿提出的盐效应机构。     

The salt effect for the solubilities of metal β-diketonates—II: Beryllium benzoylacetonate

In order to confirm extensively a generalized interpretation for the salt effect in solvent extraction of metal chelates, the solubilities of bis(1-phenyl-1,3-butanedionato) Be(II) (Be(bzac)₂) in aqueous solutions of LiCl, NaClO₄, NaNO₃, KBr, NaBr, KCl, NaCl and Na₂SO₄ were determined at 25°C. The salting coefficients of these salts for Be(bzac)₂ were obtained from the above data, and were found to accord with McDevit-Long equation except for LiCl. The salting-in effect of LiCl is discussed from the aspect of the strong hydration of small Li⁺ ion. The salting coefficients for Be(bzac)₂ are compared with those for the corresponding copper chelate (Cu(bzac)₂) and an influence of the stereochemical configurations of the metal chelates on the salt effect is also discussed.     

A study of background signals in graphite-furnace atomic absorption spectrometry

The non-specific absorption from inorganic and organic molecules between 190 and 400 nm are measured using a graphite furnace and an atomic absorption spectrometer with a deuterium source.The molecular absorption spectra of NaCl, KCl, RbCl and CsCl are very similar, with two maxima at ca. 200 and 250 nm. That of LiCl is very weak, as is that of NaF. The spectra of NaBr, NaI, KBr, KI, CaCl₂, MgCl₂, SrCl₂, FeCl₃, LaCl₃ are also reported.The non-specific absorption spectrum arising from albumin decreases fro 190 to 400 nm, and that for plasma is similar to albumin, although a contribution from inorganic salts can also be seen. To decrease the non-specific absorption from metal chlorides or biological samples of mainly inorganic composition such as urine, addition of HNO₃ is satisfactory. Oxygen introduction during low temperature charring is better for removing contribution from organic molecules.     

碱金属卤化物与NaA分子筛之间的固态离子交换反应

在低于碱金属卤化物熔点的温度下热处理碱金属卤化物和脱水NaA分子筛干混样品时,一部分分散到分子筛内孔的金属离子能够与脱水分子筛进行程度不同的固态离子交换反应,生成的非挥发性NaCl产物将扩散到分子筛笼外单独结晶或剩余的原卤化物形成溶体.热处理温度愈度,离子交换度愈大;在一定温度下热处理干混样品,存在最大离子交换度.     

不同浓度和温度时无机盐和尿素对抗抑郁剂药物丙咪嗪盐酸盐的胶束化行为的影响

In the present study we report the micellization behavior of imipramine hydrochloride(IMP)in absence and presence of different concentrations of inorganic salts(LiCl,NaF,NaCl,NaBr,and KCl)and ureas(urea and thiourea)over the temperature range from 288.15 to 303.15 K.The critical micellization concentrations(cmc)of drug and drug+additive systems were determined by conductometric technique. With increasing temperature the cmc first increases then decreases.Maximum cmc values were obtained at 293.15 K with or without additives.In presence of inorganic salts the cmc value decreases which is explained on the basis of nature and ion size of the added ion.Urea and thiourea also decrease the cmc at low concentrations(0.2 mmo·lL -1 urea and 0.1 mmo·lL -1 thiourea),but,at higher concentrations,increase in cmc is observed.The related thermodynamic parameters are also evaluated and discussed.     

Electrophilic catalysis in nucleophilic substitution reactions in ionic liquids

2-Chlorotropone was obtained from 2-tosyloxytropone in 88% yield in the recyclable ionic medium BMIMBF₄/LiCl. That Li⁺ acts as a Lewis acid was proven by the lack of reactivity of 2-tosyloxytropone, under the above conditions, on replacing LiCl with NaCl or BMIMCl, or using BMIMCl alone, or a BMIMBF₄/MeCN/KCl mixture. 2-Bromo- and 2-iodotropone were obtained along similar lines from LiBr or LiI, respectively, whereas LiF proved unreactive.     

Silver nanoplates and nanowires by a simple chemical reduction method

The critical micelle concentration (cmc) of an amphiphilic drug amitriptyline hydrochloride (AMT) was determined in the presence of varying amounts of inorganic salts (NaF, NaCl, NaBr, LiCl, KCl), urea and thiourea over the temperature range 293–308 K by conductometric and dye solubilization (ambient) techniques. The cmc values showed an inverted U-shaped behavior with temperature. In the presence of salts the cmc decreased which is explained on the basis of the nature and ion size. Urea and thiourea, at low concentrations (0.2 mM urea and 0.1 mM thiourea), decreased the cmc, whereas, at high concentrations, increase was observed with both the additives. Relevant thermodynamic parameters were also evaluated and discussed.     

Effect of alkali halide salt additives on the structure of poly(vinyl alcohol) films cast from aqueous solutions

The molecular structures of poly(vinyl alcohol) films cast from polymer aqueous solutions (1 mol/L) containing 0.1 mol/L of LiCl, NaF, NaCl, KCl, CsCl, KBr, and KI salts are studied via FTIR spectroscopy. The addition of any of these salts except LiCl leads to an increase in the degree of crystallinity of poly(vinyl alcohol) in a film by a factor of 1.3–1.6. In contrast, LiCl significantly decreases the crystallinity of the polymer. It is found that, in the IR spectra of the films containing salt additives, the position of the maximum in the band of the stretching vibrations of OH groups of the polymer is shifted relative to its position in the IR spectra of the films free of salt additives. The magnitude and direction of this band shift depend on the types (anion or cation) and radii of ions comprising salts. The observed effects are interpreted in terms of existing ideas on the interactions of salt ions with the OH groups of water and other hydroxyl-containing molecules.     

Leitfähigkeitsuntersuchungen in Hexamethylphosphorsäuretriamid und Propandiol-1,2-carbonat

Limiting conductances, dissociation constants and ion conductances have been determined for a number of tetrabutylammonium and lithium salts in the solvents hexamethylphosphoric triamide (HMPT) and propanediol-1.2-carbonate (PDC). LiCl and LiBr are completely dissociated inHMPT, but are associated inPDC. The reverse behaviour is found for the corresponding tetrabutylammonium salts. Conductance measurements show thatHMPT is a strongly differentiating solvent for the donor strength of halide and perchlorate ions.     

The apparent molal volumes of 1:1 electrolytes in urea solution. II. Variation of apparent molal volume with salt concentration

The apparent molal volumes of NaCl, NaBr, KCl, KBr, LiCl, and CsCl were measured as a function of salt concentration in 1m and 8m aqueous urea at 25°C. It was found that equations of the form $$\phi = \phi _0 + S\prime \surd \bar C + b\prime C$$ where the limiting slopeS′ is the same for all the salts in a given concentration of urea, accurately describe the data for salt concentrations less than 1M. The values found forS′ were 1.52 in 1m urea and 1.00 in 8m urea. These are in good agreement with estimated values of the Debye-Hückel limiting slope.     

间对二氯苯在盐水溶液中活度系数的研究

本文用紫外可见分光度法测定了25℃下间位和对位二氯苯在NaF,NaCI,KBr,Na~2CO~3,K~2So~4,Et~4NBr水溶液中的活度系数,Logf-c~5关系符合Setschenow 盐效应经验公式,盐效应次序为,Na~2CO~3>K~2So~4>NaF>NaCi>NaBr>Et~4NBr. 通过比较发现:二氯苯的偶极矩对盐效应几乎没有影响,本文选取Debye-Mcaulay( DMT)和Conway-Desnoyers-smith(CDST)静电作用理论,定表标粒子理论(SPT)及改进前后的内压力理论IPT和XIPT),计算出理论值,与实验值进行比较, 证实的内压力理论计算值更接近实际.     

Interaction of water with LiCl, LiBr, and LiI in the deeply supercooled region

The hydration mechanism of lithium halides was studied using time-of-flight secondary ion mass spectrometry as a function of temperature. The lithium halides embedded in thin films of amorphous solid water segregate to the surface at temperatures higher than 135-140 K, with efficiency increasing in the order of LiCl, LiBr, and LiI. A monolayer of LiCl and LiI adsorbed on the surface of amorphous solid water tends to diffuse into the bulk at 160 K. The infrared absorption band revealed that the aqueous lithium-halide solutions and crystals are formed simultaneously at 160 K; these phenomena are explicable as a consequence of the evolution of supercooled liquid water. The strong surfactant effect is inferred to arise from hydration of a contact ion pair having hydrophilic (lithium) and hydrophobic (halide) moieties. Furthermore, bulk diffusion of lithium halides might result from the formation of a solvent-separated ion pair in supercooled liquid water. The presence of two liquid phases of water with different local structures is probably responsible for the formation of these two hydrates, consistent with the calculated result reported by Jungwirth and Tobias[J. Phys. Chem. B 106, 6361 (2002)].     

电解质在混合溶剂中的溶解度——盐-DMSO(或DMF)-惰性溶剂体系

本文测定了盐在含苯、甲苯、对二甲苯和四氯化碳的DMSO或DMF混合溶剂中的溶解度。结果符合经验公式lg(S₀/S_m)=K^φφ_Ne;对K^φ的规律作了初步讨论。