Solutions Of Alkali Metals Research Articles

Preparation and structure of alkali metal intercalation compounds

The preparation methods of intercalation compounds fall into four main groups: use of alkali metal solutions in liquid ammonia, organometallic reagents, electrochemical methods, and solid state processes. Each of these will be briefly described and a general comparison of the advantages and disadvantages will be made. Structural problems concern the positions occupied by the guest ions and their mobility from one site to one another in the host structure. The resulting ionic conductivity of the intercalation compounds depends on factors such as the ratio between available and occupied sites in the van der Waals gap, the ionicity of the bonds in the host structure, the site geometry, and the nature of the alkali metal.

Ion-pairing and electron spin resonance spectra of solutions of alkali metals in polar solvents

Electron spin resonance (ESR) spectra of solutions of potassium in mixtures of ethylamine and ethylenediamine are reported. It is shown that a simple ion-pairing treatment is quantitatively capable of predicting the form of the ESR spectra in this system and in a wide variety of other metal-solvent systems.

Application of the radiotracer method in ion exchange studies of the complex formation process in the zinc chloride system. Effect of the macroelectrolyte cation

The distribution coefficients of zinc labelled with 65Zn between Dowex 50 W × 8 cation exchange resin and aqueous solution of LiCl, NaCl, KCl, CsCl, or HCl have been obtained by the radiotracer method. The measurements were performed at 21°C and constant ionic strength (0.7 M) using HClO 4, HNO 3, LiNO 3, NaNO 3, KNO 3 or CsNO 3 respectively as inert electrolyte. The stability constants of the mononuclear chloride complexes of zinc were determined and the validity of the relation β n = A( a n / n!) has been demonstrated, where β n is the overall stability constant of the ML n complex, A and a are characteristic parameters of the metal-ligand system. Expressing the complexity function in terms of the above relation yielded four parametric expressions for the distribution coefficient (same for all alkali-metal solutions); two of the parameters are related to the exchange equilibrium of Zn 2+ and ZnCl + and the other two to the complex formation process in the aqueous phase.

Density of states in the gap of a disordered material using E.S.R./optical correlations

Abstract Electron-spin-resonance studies of rapidly frozen solutions of alkali metals in anhydrous hexamethylphosphoramide (HMPA) indicate the presence of several, distinct localized electron states. Optical studies of similar species in a variety of fluid solutions reveal a simple correlation between the optical transition energy and the degree of occupation of the alkali-metal ns orbital. From this information we evaluate a distribution function for the various (localized) paramagnetic states present in the low-temperature disordered system. The localized states assume only a few, discrete eigenstates within the host (HMPA) bandgap. We speculate on the possible origin of these states; particular emphasis is placed upon the influence of lone-pair electrons and steric effects in determining the molecular configurations of the host matrix around the alkali atom during the quenching process. We point out the striking similarities between the eigenfunctions/eigenstates of matrix-bound states and the excited ...

Solvated electrons and the effect of coordination on the optical spectra of alkali metal cation – electron pairs in ethers

Pulse radiolysis of tetrahydrofuran (THF), dimethoxyethane (DME), diglyme (DG), and triglyme (TG), results in the formation of solvated electrons, es−, with optical band maxima λmax ≥ 1840 nm. In the presence of alkali metal salts transient optical bands are observed with λmax at ∼900 and ≥1600 nm. The latter bands are assigned to the formation of 'monomeric' species of stoichiometry M considered to be 'tight' and 'loose' ion-pairs, respectively. The proportion of 'loose' ion-pairs increases with decreasing temperature and increasing coordination of the solvent in the order [Formula: see text] These results demonstrate a good correlation with established electron spin resonance data in alkali metal solutions and substantiate the coexistence of at least two 'monomeric' species in DME and the glymes.

Surface tension of molten cadmium + cadmium halide solutions

The isotherms of the surface tension of solutions of Cd in CdX 2 (XCl, Br, I), as functions of the mole fraction of dissolved cadmium, have been determined by the maximum-bubble-pressure method. The influence of dissolved cadmium upon the surface tensions of the three solutions has been discussed by comparing it with the excess molar volumes of these solutions. Also Bertozzi and Soldani's surface tensions of solutions of MCl in CdCl 2 (M = alkali metal) solutions have been used in the discussion.

Correlation of optical and electron spin resonance spectra for metal–electron species in alkali metal solutions

Pulse radiolysis of alkali metal cations (M+) in amines and tetrahydrofuran has demonstrated the formation of transient optical absorption bands attributed to a species of stoichiometry M. Such bands exhibit a distinct blue shift from that of es− observed in the same solvent. Comparisons with electron spin resonance (esr) spectra obtained in alkali metal solutions demonstrate that the blue shift can be correlated with the percent atomic character deduced for the species of the same stoichiometry. This correlation indicates that both the optical and esr spectra arise from the same species which, with decreasing solvent polarity, exhibits a continuous transition from well solvated ion-pairs to something approaching solvated atoms or tight ion-pairs.

Physico-chemical studies in nonaqueous solvents. Part 13.—Thermochemical studies of some 1 : 1 electrolytes in tetramethylurea

Heats of solution of alkali metal, ammonium and substituted ammonium perchlorates, lithium and sodium bromides and sodium and potassium thiocyanates have been measured in the concentration range 1.75–67.7 × 10–3 mol dm–3 in tetramethylurea (TMU) at 26.9°C. Slopes of the linear plots of heat of solution against square root of concentration of the electrolytes (except for NaClO4 and KSCN) are 2 to 9 times higher than the theoretical limiting slope, suggesting thereby slight association of these electrolytes in TMU. However, the experimental slopes of the plots of NaClO4 and KSCN are comparable to the theoretical plot, showing complete dissociation of these electrolytes. Ion solvation enthalpies have been computed using a modified Buckingham's model. The results indicate that ion solvation enthalpies decrease with the increase in the size of the ions, which is consistent with findings in other solvents.

Infrared spectral studies of ion association in nonaqueous solutions of cyanide salts with consequences for their nucleophilic reactivity

An infrared spectrometric study of alkali metal and tetraphenylarsonium cyanide (AsΦ4CN) solutions in DMSO or DMF shows that even for concentrations of 0.1M a large proportion of the ions are associated. The order of basicity established through methanol Δν(OH) frequency shifts is CN−>Cl−>Br−. Addition of common ions or cyclic polyether to these solutions, as well as correlations between the ν(CN−) frequencies and those of the ν(C≡N) bands of CH3CN bonded to the same cations, suggests assignments of the observed bands to solvated contact ion pairs M+ CN−, triple ions M+ CN− M+, and aggregates (M+ CN) n − . The nucleophilic reactivity of these salts is related to the structure of these solutions.

Correlation of optical and electron spin resonance spectra for alkali metal solutions in ethylamine and tetrahydrofuran

The band maxima of transient optical absorption spectra observed by pulse radiolysis in ethylamine (EA)/tetrahydrofuran (THF) mixtures containing sodium tetraphenylboron are correlated with electron spin resonance (esr) hyperfine splitting constants obtained in potassium/EA/THF solutions. The data suggest that the optical spectra can be attributed to the same 'monomeric' species as observed by esr in alkali metal solutions.

Magnetic properties of intermediate impurity states in frozen solutions of alkali metals in hexamethylphosphoramide

Electron spin resonance spectra at 77 K show the existence of several, discrete, intermediate impurity states which differ markedly in the percent occupation of the metal outer ns orbital. It is proposed that an amorphous matrix allows impurity states to assume only certain discrete eigenstates within the bandgap.

Hydrogen in liquid alkali metals

The chemistry of liquid alkali metal-hydrogen solutions has been surveyed. Solubility data for hydrogen (<6 mol% H) and deuterium (<4 mol% D) in liquid lithium are reported, Li-H log S(mol% H) = 3.523 − 2308/T(°K) Li-D log S(mol% D) = 4.321 − 2873/T(°K), and the isotope effect considered. The hydrogen data are used to augment the LiLiH phase diagram and are compared with corresponding solubilities in sodium, potassium and eutectic NaK (78 wt.% K) alloy; data for rubidium and caesium are not available. The nature of the solute species and the concept of solvation in these solutions are also discussed.Investigations of interactions between hydrogen and non-metals in liquid alkali-metal solutions have shown that, whereas hydrogen and nitrogen act independently in lithium at 420 °C, hydrogen and oxygen interact in sodium at 400 °C according to the equilibrium: O2− + H−⇌ OH− + 2e−. Hydrogen-oxygen interactions in the other alkali metals are also considered and are rationalised in terms of the enthalpy changes of the corresponding solid-state reaction. Furthermore, yttrium has been shown to react, rapidly, with hydrogen dissolved in lithium at a relatively low temperature (400 °C) to form a mixture of a solid solution of hydrogen in yttrium and yttrium dihydride according to the reaction: Li(H) + Y → Li + Y(H) + YH2−x.

Pulse radiolysis of alkali metal cations in isopropylamine: Correlation of optical absorption spectra with electron spin resonance data

Pulse radiolysis of alkali metal cations in isopropylamine indicates the formation of three distinct optical bands attributed to solvated electrons, e − s, ion-pairs (M +, e − s) and alkali anions M −. It is found that the ion-pair spectra exhibit a distinct blue shift from that of e − s. Comparisons with results obtained in ethylamine, tetrahydrofuran and other solvents demonstrate that the position of the ion-pair band can be correlated with the percent atomic character observed by ESR for the “monomer” species in alkali metal solutions. Results are presented for the alkali metal series, Li, Na, K, Rb and Cs.

Physico-chemical studies in non-aqueous solvents Part XII. Thermochemical studies of some 1:1 electrolytes in N,N-dimethylacetamide

Heats of solution of alkali metal, silver, ammonium and substituted ammonium perchlorates, lithium chloride and potassium thiocyanate have been measured in the concentration range 1.26–112.8×10−3 mol l−1 in N,N-dimethylacetamide (DMA) at 26.9°C. Slopes of the linear plots of heat of solution vs. square root of concentration are two to three times higher than the Debye-Hückel limiting slope indicating thereby complete dissociation of the electrolytes. Standard heats of solution of the electrolytes in DMA are higher than those in formamide and N-methylformamide and are comparable to those in N,N-dimethylformamide. Buckingham's model has been used to determine the solvation enthalpies of various ions in this solvent. The results indicate that ion solvation enthalpies decrease with increase in size of the ions and that the anion solvation enthalpies are higher than cation solvation enthalpies which is consistent with the findings in various solvents.

Physico-chemical studies in non-aqueous solvents: Part XII. Thermochemical studies of some 1:1 electrolytes in N,N-dimethylacetamide

Heats of solution of alkali metal, silver, ammonium and substituted ammonium perchlorates, lithium chloride and potassium thiocyanate have been measured in the concentration range 1.26–112.8×10 −3 mol l −1 in N,N-dimethylacetamide (DMA) at 26.9°C. Slopes of the linear plots of heat of solution vs. square root of concentration are two to three times higher than the Debye-Hückel limiting slope indicating thereby complete dissociation of the electrolytes. Standard heats of solution of the electrolytes in DMA are higher than those in formamide and N-methylformamide and are comparable to those in N,N-dimethylformamide. Buckingham's model has been used to determine the solvation enthalpies of various ions in this solvent. The results indicate that ion solvation enthalpies decrease with increase in size of the ions and that the anion solvation enthalpies are higher than cation solvation enthalpies which is consistent with the findings in various solvents.

Electron spin resonance studies of localized excess electron states in frozen solutions of alkali metals in hexamethylphosphoramide

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron spin resonance studies of localized excess electron states in frozen solutions of alkali metals in hexamethylphosphoramideRon Catterall and Peter P. EdwardsCite this: J. Phys. Chem. 1975, 79, 26, 3010–3017Publication Date (Print):December 1, 1975Publication History Published online1 May 2002Published inissue 1 December 1975https://doi.org/10.1021/j100593a044RIGHTS & PERMISSIONSArticle Views37Altmetric-Citations22LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (748 KB) Get e-Alerts

Electron spin resonance studies of extended excess electron states in frozen solutions of alkali metals in hexamethylphosphoramide

Electron spin resonance studies of extended excess electron states in frozen solutions of alkali metals in hexamethylphosphoramide

Pulse Radiolysis of Alkali Metal Solutions in Methylamine

Pulse radiolysis studies of solutions of alkali metal methylamides (CH3NHM) in methylamine indicate the formation of solvated electrons, es−, ion-pairs (M+, es−), and alkali metal anions M−. This paper compares the spectra, extinction coefficients, and yields of es−, Li, Na, K, and Cs species, with those observed previously in other solvents. The overall reaction kinetics are complex and, in CH3NHNa/NaI solutions, suggest the formation of a higher aggregate or triple ion species (Na22+, es−). A reaction mechanism, quantitatively consistent with experiment, is presented and discussed in detail for solutions containing Na+.

Use of dicyclohexyl‐18‐crown‐6 in anionic polymerization. I. Solutions of alkali metals in benzene and in tetrahydrofuran

Use of dicyclohexyl‐18‐crown‐6 in anionic polymerization. I. Solutions of alkali metals in benzene and in tetrahydrofuran

Pulse Radiolytic Formation of Solvated Electrons, Ion-pairs, and Alkali Metal Anions in Tetrahydrofuran

Pulse radiolysis of solutions of alkali metal cations in tetrahydrofuran (THF) demonstrates the formation of solvated electrons es−, alkali metal cation-ion pairs (M+, es−), and alkali metal anions M−. This paper describes the spectra, extinction coefficients, and radiolytic yields of es−, lithium, sodium, potassium, and cesium species in THF. The reaction kinetics are complex but largely involve reactions A and B[Formula: see text]with the concomitant disappearance of all three species by reaction with radiolytically produced radicals. Rate constants and ion-pair dissociation constants for es− and the sodium and potassium species are presented and compared with data established from studies of blue solutions of alkali metals dissolved in THF.