The volume transition induced by monovalent-divalent cation exchange of fully neutralized polyacrylate hydrogels was investigated in aqueous NaCl solutions. The variation of the osmotic swelling pressure, shear modulus, and mixing pressure was measured when Na(+) ions were substituted by divalent or trivalent cations. Alkali metal salts move freely throughout the entirely network, and alkaline ...

Novel di-ionizable p-tert-butylcalix[4]arene-1,2-crown-3 ligands in cone and 1,2-alternate conformations were prepared as potential metal ion extractants. Selective bridging of proximal hydroxyl groups of the calix[4]arene platform by a crown-3 polyether unit was achieved under Mitsunobu reaction conditions. In addition to the carboxylic acid group, the acidity tunable N-(X)sulfonyl oxyacetamid...

A thio carboxylic acid derivative: 2-aminocyclopent-1-ene-1-carbodithioic acid (ligand) was synthesized and characterized. It was used as a colorimetric chemo sensor (chads) for Ni. The absorption maximum of ligand and Ni shows a shift from 390 nm to 420 nm in absence of buffer solutions. The change in color is very easily observed by the naked eye, while other metal cations, such as Fe, Co, Hg...

Layered ternary chalcogenides AxMX2 (A = al­ kali metal, M = transition metal, X = S, Se) of group IV b to VI b elements may be prepared either by reactions a t high temperatures (600-1000 °C) from the elements1 and via alkali halide m elts2 or at low temperatures from the corresponding binary phases MX2 by intercalation of alkali metals from liquid ammonia3. Both series of compounds were found...

Novel 2-benzothiazole-, 4-pyridine-, and 2- and 4-quinoline-based styryl dyes containing an N-methylbenzoaza-15(18)-crown-5(6)-ether moiety were synthesized. A detailed electronic spectroscopy study revealed high performance of these compounds as optical molecular sensors for alkali and alkaline-earth metal cations. They were shown to considerably surpass analogous chromoionophores based on N-p...

The title compound, sodium disilver arsenatotrimolybdate, Na(0.93 (1))Ag(2.07 (1))Mo(3)AsO(13), was prepared by a solid-state reaction. In the crystal structure, isolated AsO(4) tetra-hedra share corners with groups of three edge-sharing MoO(6) octa-hedra. This arrangement leads to the formation of anionic (1) (∞)[Mo(3)AsO(13)](n) ribbons extending parallel to [100]. The three metal sites show ...

The constants of the extraction equilibrium and the distribution for dichloromethane as an organic solvent having low dielectric constant of metal cations with chiral Schiff bases, benzaldehydene-(S)-2-amino-3-phenylpropanol (I), ohydroxybenzaldehydene-(S)-2-amino-3-phenyl-propanol (II), benzaldehydene-(S)-2amino-3-methylbutanol (III) with anionic dyes [4-(2-pyridylazo)-resorcinol mono sodium m...

Organo-Zintl cluster ions were synthesized by reactions of alkynes with Ge94- clusters in ethylenediamine. The triple bonds are hydrogenated to double bonds during the process. The resulting dial-kenylated species [RHC=CHGe9CH=CHR]2- have lower charge, their alkali-metal cations can be exchanged for tetralkylammonium cations, and the resulting compounds are soluble in nonpolar solvents. This wa...

The box-like cages {M[Cp*Rh(CN)3]4[Mo(CO)3]4} form as the sole metal-containing products of the reaction of [Cp*Rh(CN)3] and (η-C6H3Me3)Mo(CO)3 in the presence of K+ and Cs+. Well-defined species could not be identified in solutions of Cp*Rh(CN)3 and (η-C6H3Me3)Mo(CO)3 in the absence of alkali metal cations. The new cages were isolated as their Et4N salts, M ) K+ (1), Cs+ (2). Crystallographic ...

The selective preference of Chlorella pyrenoidosa for alkali metal cations was found to have the order Rb > K > > > Na. It was demonstrated that a cation of higher preference can replace in the cell cations of lower preference by an ion interchange process.The replacement of Na from the cell by K or Rb occurred against high external Na concentrations up to 450 meq/1 Na.It is suggested that the ...