Alkali Earth Metal Cations Research Articles

ChemInform Abstract: Amide‐Armed Azamacrocycles as a New Series of Synthetic Carriers for Alkali and Alkaline Earth Metal Cations.

AbstractCation transport profiles of the azamacrocycles (I)‐(V) for Li, Na, K, Cs, Mg, Ca and Ba are listed in a table.

Perkin communications. Amide-armed azamacrocycles as a new series of synthetic carriers for alkali and alkaline earth metal cations

Novel azamacrocycles having amide-functionalized arm groups have been shown to mediate selective and efficient transport of ‘hard’ alkali and alkaline earth metal cations via three-dimensional complexations, while the parent azamacrocycles favour ‘soft’ metal cations.

Substitution‐Inert Metal Complex Mobile Phases in Non‐Suppressed Cation Chromatography

AbstractSubstitution‐inert metal complexes, [Co(edda)(H2O)2]+, (Co(edda)(en)]+, [Co(edda)(dmen)]+, [Co(en)2‐(gly)]2+, [Co(en)2(acac)]2+, and [Co(trien)(gly)]2+ in their nitrate salt solutions are used as eluents in nonsuppressed cation chromatography (where edda = ethylenediamine‐N,N′‐diacetic acid, en = ethylenediamine, dmen = N,N′‐dime‐thylethylenediamine, gly = glycine, acac = acetylacetone, and trien = triethylenetetraamine). It is found that all the mono‐ and di‐valent charged complexes can be used to separate alkali and alkaline earth metal cations, respectively. The separations for monovalent cations are sometimes comparable to those using ultrapure HNO3 solutions. However, the divalent Ca2+ and Sr2+ ions cannot be resolved using the metal complex eluents. On the other hand, a selected, direct non‐suppressed IC separation of zinc(II) and cadmium(II) ions is demonstrated for the first time using a substitution‐inert metal complex eluent and a conductivity detector. Comparisons of these eluents with those reported previously, i. e. HNO3 and ethylenediammonium salt solution are made and explanations are proposed to account for the different selectivities observed where possible. The future development of this technique is also briefly discussed.

Active Transport of Alkali and Alkaline Earth Metal Cations by Oligo (oxyethylene) Alkyl Ethers Bearing a Carboxyl Group

Dodecyl oligo(oxyethylene)carboxymethyl ethers (1 )and 2-[oligo(oxyethylene)]octadecanoic acids (2) were prepared by the method shown in Scheme-1. They were examined for their capacity to function as cariers for the active and competitive transport of alkali (Li+, Na+, and K+) and alkaline earth (Mg2+, Ca2+, and Ba2+) metal cations in chloroform membrane systems.Simple alkanoic acid, i.e. dodecanoic acid failed to mediate the transport of any cation in the present systems, but (1) and (2) with an appropriate number of oxyethylene units (m) effectively transported the cations, confirming the validity of introduction of the oligo (oxyethylene) chain into alkanoic acids.For the transport of alkali metal cations, carriers with m≥4 were effective, and those with m≥5 were superior in K+-selectivity to those with m=4. All (1) and (2) transported Ca2+ and Ba2+ with higher efficiency but lesser ion-selectivity than in the case of alkali metal cations.The results are discussed based on “host-guest” relationship between the cavity size of pseudocyclic oligoethers and cation diameter, and on lipophilicity and rigidity of complexes formed from carrier molecules and cations.

Effect of cations on the phosphorescence properties of acetophenone derivatives with a Crown Ether Moiety

The phosphorescence quantum yields (ϕp) of acetophenone derivatives bearing a crown ether moiety are markedly altered by complexation with alkali and alkaline earth metal cations.

Passive Transport of Alkali and Alkaline Earth Metal Cations by Cooperative Carrier Composed of n-Alkyl Oligo (oxyethylene) Ether and Alkanoic acid

Homogeneous oligo(oxyethylene)n-dodecyl ethers(C12Em, m=28)and higher alkanoic acids(C8C18)were examined as carriers for the competitive passive transport of alkali(Li+, Na+, and K+)and alkaline earth metal(Mg2+, Ca2+, and Ba2+)cations through a chloroform membrane.1) The linear polyethers, combined with an alkanoic acid, effectively mediated cation-transport similarly to cooperative carriers composed of crown ether and alkanoic acid as reported previouslyl4)16).2) 2-Bromoalkanoic acids (BAA) were superior to those unsubstituted as co-carriers in both transport efficiency and cation-selectivity for two competitive systems (Table-1 and -2).3) For a monovalent cations system, the polyethers combined with BAA (C12Em-BAA) had essentially the same selectivity (K+>Na+>>Li+). Their transport efficiency increased with m (Fig.-3).4) The selectivity of divalent cations except Mg2+ was found to depended on m of C12Em-BAA, and plots of efficiency vs. m for Ca2+ and Ba2+ gave maxima at m=5 and m=6, respectively (Fig.-5).5) The effect of the acyl chain length of BAA on the transport ability of these cooperative carriers was also examined (Fig.-4 and -6).

On the Glass in Coal Fly Ashes: Recent Advances

ABSTRACTRecent advances in the characterization of the glassy aluminosilicate phases in coal fly ashes are reviewed and discussed in terms of the development of new models describing their mechanism of formation, composition, structural relationships and chemical reactivity. Characterization techniques such as electron microscopy, x-ray diffraction, infrared and Raman spectroscopy, nuclear magnetic resonance and Mössbauer spectroscopies, thermal analysis, acid dissolution, silanation, and density fractionation have been used as experimental probes, and reveal a range of information relating to the glass phases from the macro, through the micro, to the nano-structural levels. Complex inter- and intra-particle heterogeneity in ash is observable not only in bulk chemical and mineralogical analyses but also at the molecular level in the constituent glasses. Remarkable relationships between ash particle size, density and glass composition have been observed and lead to a new proposed mechanism for ash morphogenesis based on temperature-viscosity effects in the mineral precursor melts in the boiler flame. A glass-ceramic model for fly ash particle structure is proposed and discussed in terms of phase relations in the CaO–SiO2–Al2O3 and FeO–Fe2O3–A12O3–SiO2 systems, modification of the aluminosilicate glasses by alkali and alkaline earth metal cations, and microheterogeneity involving glass devitrification and phase separation.

The Chromatographic Behavior of Alkali and Alkaline Earth Metal Cations on Crown Ether-Modified Silica Gels and Polymer Matrices

Abstract Alkali and alkaline earth metal cations were chromatographed over silica gels and polymer matrices which had been modified by the addition of benzo-15-crown-5, benzo-18-crown-6, and benzo-21-crown-7, using water as the mobile phase. The retention sequences of the cations agreed closely with the stability sequences of the corresponding crown-ether complexes. The best separation was attained on the silica gels modified by the use of benzo-18-crown-6. The retention times increased in this sequence: Li+<Na+<Rb+<Cs+<K+; Mg2+<Ca2+<Sr2+<Ba2+. The retention sequences on the benzo-15-crown-5 and benzo-21-crown-7 columns were Li+<Na+≈Cs+<Rb+<K+ and Li+≈Na+<K+<Rb+≈Cs+ respectively. The resin-based columns showed similar retention sequences, but were inferior in their separation ability to the silica-based ones. The retention times were affected by many factors, such as the cation concentration, the species of the counter anions, the kind and composition of the second solvents in the mixed mobile phase, and the column temperature.

Cation binding properties of poly(crown ethers) with photodimerizable groups

AbstractPolymers that have crown ether groups as cation binding sites and cinnamic acid ester groups as photodimerizable groups were prepared by the cationic polymerizations of 2‐vinyloxyethyl 4′‐(2,3‐benzo‐1,4,7,10,13‐pentaoxa‐2‐cyclopentadecene)acrylate and 2‐vinyloxyethyl 4′‐(2,3‐benzo‐1,4,7,10,13,16‐hexaoxa‐2‐cyclooctadecene)acrylate. When irradiated with ultraviolet (UV) light the cinnamic acid ester groups of the polymers caused dimerization in dilute solution without the formation of insoluble materials. The irradiation was carried out in a dioxane solution and an aqueous solution in the presence and absence of salts. The effect of phototransformation of polymers on the cation binding properties was investigated by a method of picrate salts extraction. The binding ability of the phototransformed polymers for alkali and alkaline earth metal cations was higher than that of the native polymer. Furthermore the cation binding ability of the phototransformed polymers was less sensitive to temperature than that of the native polymer. The effect of the degree of photodimerization of the polymers and the concentration of KCl that exists during irradiation on the cation binding ability was also investigated.

The relationship between the corrosion resistance and impurity content of aluminium oxide layers

In the last few years there has been an increased production and application of aluminium foil of under 20 μm thickness all over the world. Household foil is often stored in a wet environment, where the surface is only protected against corrosion by an aluminium oxide layer produced during manufacturing. In this study it has been shown that the aluminium-water vapour reaction is greatly affected by the composition and structure of the amorphous oxide layer on the surface and this depends on the composition of base metal and on the annealing of the foil. The incubation period of aluminium hydroxide nucleation is shortened and its growth rate accelerated by alkali and alkaline earth metal cations incorporated in the oxide layer. In particular the corrosion resistance is decreased by the presence of alkali (Li) and alkaline earth metal (Mg) cations in the oxide layers.

Synthesis and Properties of Crown Compounds Containing Anthraquinone Nuclei

Abstract 2,5,8,20,23,26-Hexaoxa[7.7]-and 2,5,8,11,23,26,29,32-Octaoxa[10.10](1,8)anthraquinonophanes (2 and 3) were synthesized, examined for complexation behavior with alkali and alkaline earth metal cations, and observed to show significant selectivity among the cations studied. The electroreduction of 2 by cyclic voltammetry was studied with there lated compounds.

Lipophilic Diamides as Ionophores for Alkali and Alkaline Earth Metal Cations

AbstractA series of lipophilic N, N, N′,N′‐tetrasubstituted diamides were prepared and their selectivity in solvent polymeric membranes was studied, cis‐N, N, N′, N′‐Tetraisobutylcyclohexane‐1,2‐dicarboxamide induces a selectivity in membranes for Li+over alkaline earth metal cations and other alkali metal cations by a factor of about 1000 and 100 respectively. The ionophore N, N′‐diheptyl‐N,N′‐dimethylethylmalonamide is an attractive candidate for the use in microelectrodes for the determination of intracellular Mg2+‐activities.

Preparation and properties of stationary phases containing immobilized, electrically neutral non-macrocyclic ionophores for liquid—solid chromatography

Novel stationary phases for liquid—solid chromatography have been prepared by immobilizing electrically neutral, non-macrocyclic ionophores on porous glass, silica and styrene—divinylbenzene copolymers. The chromatographic behaviour of these sorbents is described. They show selectivity for alkali and alkaline earth metal cations and have been used to separate such ions.

ChemInform Abstract: LIPOPHILIC AMIDES OF EDTA, NTA AND IMINODIACETIC ACID AS IONOPHORES FOR ALKALINE EARTH METAL CATIONS

AbstractDie Selektivität von Lösungsmittel‐Polymer‐Membranen (mit o‐Nitrophenyl‐octyl‐ether als Membranlösungsmittel) für Alkali‐ und Erdalkalimetall‐ Ionen wird durch den Einbau von neutralen, lipophilen Di‐, Tri‐ oder Tetra‐amiden erheblich verändert.

The synthesis and complexation of open chain polyethers having various end groups

The syntheses of a series of oxygen containing ligands of general formula o-ROC 6H 4O(CH 2CH 2O) n oC 6H 4OR′ are described; the complex formation of these ligands with alkali and alkaline earth metal cations has been investigated. Stability constants for sodium and potassium increase as n is increased from 1 to 3, as R is varied through the series, H, CH 2C 6H 5, CH 2CH 2OH, CH 2CO 2C 2H 5, CH 2CO 2H. When R and R′ are different, the stability constant is intermediate between that found when both end groups are R and that when both are R′. In these compounds there is no evidence for the presence of internal hydrogen bonding contributing to the stability of the complexes.

Lipophilic Amides of EDTA, NTA and Iminodiacetic Acid as Ionophores for Alkaline Earth Metal Cations

AbstractA series of electrically neutral lipophilic di‐, tri‐, and tetra‐amides containing tertiary‐amine N‐atoms were prepared in order to investigate their selectivity for alkali and alkaline earth metal cations in solvent polymeric membranes. Considerable selectivity changes were observed for membranes incorporating certain of these ligands as compared with ligand‐free membranes. A 1:1 cation/ligand complex was isolated from N, N′, N″‐triheptyl‐N, N′, N″‐trimethyl‐nitrilotriacetamid and Mg (SCN)2 whereas with Ca (SCN)2 the corresponding 2:3 cation/ligand complex was formed. N, N′, N″, N‴, N‴‐tetramethyl‐ethylenediaminetetraacetamide yields a 1:1 cation/ligand complex with Mg (SCN)2.

A barium ion-selective electrode based on the neutral carrier n, n, n', n'-tetraphenyl-3,6,9-trioxaundecane diamide

A barium-selective liquid membrane electrode based on a neutral carrier3 $ ̄ N, N, N', N' tetraphenyl-3,6,9-trioxaundecane diamide — in a poly( vinyl chloride) matrix is described. The sensor discriminates against alkali and alkaline earth metal cations by factors in the range of approximately 10 221̄0 3 and 3021̄0 5, respectively. In contrast to earlier systems, the electrode shows an excellent e.m.f. stability (the drift is less than 0.8 mV/d) and an operational lifetime of more than two years

Komplexbildung von Ionophoren vom Typ der Dioxakorksäurediamide mit Alkali‐ und Erdalkaliionen. Stabilitätskonstanten in Äthanol

Complex Formation of Ionophores of the Dioxaoctane Dicarboxylic Acid Diamide Type with Alkali and Alkaline Earth Cations. Stability Constants in Ethanol.Stability constants are reported for two noncyclic, neutral ionophores in interaction with alkali and alkaline earth metal cations in ethanol. The ligands studied give high selectivity of alkaline earth in respect to alkali metal cations when used in liquid membrane electrodes.

Preparation of Neutral Ionophores for Alkali and Alkaline Earth Metal Cations and their application in ion selective membrane electrodes

AbstractThe preparation of a series of non‐cyclic, uncharged ligands able to selectively complex alkali and alkaline earth metal cations is described. These molecules are designed to be used as carriers for cations through membranes. Some of the compounds show high Ca2+ and Na+ selectivity, respectively, in liquid membrane electrodes.

Surface acidity of imogolite and allophane

AbstractThe acid strength and the number of acid sites on various clays were determined by observing the colouration of Hammett indicators adsorbed on them and by titrating benzene suspensions of them with n-butylamine, respectively. H(Al)-saturated allophane behaves as a strong acid (Ho; −5·6 ∼ 1·5) in a relatively dry environment (relative humidity 10-55%), but its acid strength is very much reduced either by increasing its water content or by saturating it with alkali or alkali earth metal cations. Imogolite shows only a very weak acidity (Ho; 4·6 ∼ 6·8) under medium dry to moist conditions (relative humidity; 30-100%). Both allophane and imogolite show a marked enhancement of acidity (Ho; −8·2 ∼ 1·5) when they have been dried over P2O5 or heated to result in dehydroxylation. H(Al)-saturated montmorillonite, kaolinite and halloysite show stronger acidities (Ho; −5·6 ∼ 1·5) than allophane (Ho; 1·5 ∼ 6·8) in a relatively moist environment (relative humidity; >60%). The n-butylamine titre and CEC show a good agreement for montmorillonite, but a poor agreement for allophane. The latter discrepancy which is larger for allophane when it has been heated at 150 and 300°C, is also found for imogolite when similarly heated. In these titrations, excess butylamine is found in supernatants at end-points. Therefore, the n-butylamine titre as such can not be used for the estimation of the number of acid sites on imogolite and allophane. The origin, structure and transformation of the acid sites on these clays is discussed.