Aqueous Solutions Of NaSCN Research Articles

Synthesis, crystal structure, and properties of sodium heptafluorodiantimonate(III) hydrate (NaSb2F7·H2O)

A new compound NaSb2F7·H2O (I) has been synthesized from aqueous solutions of NaSCN and SbF3 (components molar ratio 0.5:1) and investigated by means of the methods of chemical, X-ray structural, and thermal analysis and IR, 121,123Sb NQR, and 1H, 19F NMR spectroscopy. The structure of I is composed of Na+ cations, H2O molecules, and asymmetric dimeric [Sb2F7]− complex anions. The anions are composed of two trigonal [SbEF4] bipyramids, in which Е is a lone electron pair of antimony(III) atoms linked through the bridge fluorine atom. Complex anions in the structure are linked through secondary Sb⋯F bonds (2.628–3.344Å), NaF bonds (2.270–2.387Å), and OH⋯F hydrogen bonds (2.727–2.837Å) into a framework. In the temperature range 90–150K, the compound I manifests piezoelectric properties in the radio-frequency field. The complex fluoride sublattice remains rigid in the temperature range 150–343K in accordance with the 19F NMR data. Upon recrystallization from water and heating in the temperature range 343–423K, the substance under study decomposes with the formation of stable complexes NaSb3F10 and NaSbF4 known from the literature.

Étude cinétique de réaction de polymérisation de l'acrylonitrile dans des solutions aqueuses de NaSCN amorcée par Mn(C 5H 7O 2) 2NCS

The kinetics of polymerization of acrylonitrile (AN) in aqueous solutions of NaSCN, initiated by Mn(C 5H 7O 2) 2NCS, was examined. Conversion and molecular weight were measured. The order of reaction in relation to monomer, the order of reaction in relation to initiator, the rate constant of polymerization, the ratio of rate constants K p K 0.5 t and the total activation energy of polymerization were determined. An initiating mechanism was proposed and it is believed to be with free radicals.

Influence of additives to the eluent on hydrophobic interaction chromatography of simple compounds : V. Influence of pH and electrolytes on the retention of n-alkylammonium ions and n-alkyl carboxylates

The retention of n-alkanoic acids and n-alkylamines on octyl-Sepharose was measured as a function of pH at a constant sodium chloride molality. The retention of n-alkylammonium ions was measured in aqueous solutions of NaSCN, NaCl, NaH 2PO 4, Na 2SO 4, KBr and MgCl 2, and that of n-alkanoate ions in aqueous solutions of NaSCN, NaCl, Na 2SO 4, trisodium citrate and KBr. The results are discussed in terms of a modified double-layer adsorption model.

Influence of additives to the eluent on the hydrophobic interaction chromatography of simple compounds : IV. Influence of electrolytes on the retention of normal alkanols at 25°C

The chromatographic retention volumes of n-alkanols on two octyl-agaroses with different octyl contents were measured at 25°C. The eluents were aqueous solutions of NaSCN, NaClO 4, NaBr, NaCl, sodium acetate, NaH 2PO 4, Na 2SO 4, Na 2HPO 4 trisodium citrate, KSCN, KCl, KBr, K 3Fe(CN) 6, MgCl 2 and CaCl 2. Salting-out constants, including those of molecular fragments, were calculated, compared with literature values and related to the molar surface tension increments of the salts in water.

Complexes of organometallic compounds. XXXVIII. Anion Exchange Studies on the Trimethyllead (IV) Thiocyanate aqueous complex system

AbstractThe distribution of Me3PbIV between the anion exchange resin Dowex 1 X 8 and aqueous solutions of NaSCN and KSCN was investigated. In the aqueous phase, up to 3 M thiocyanate concentration, only the formation of the neutral species Me3PbNCS was detected and the related stability constant evaluated. Evidence of formation into the resin phase of the anionic Me3Pb(NCS) species was obtained.

A study of shaped fiber formation

An experimental study has been carried out to investigate the effects of spinning conditions on the shape of fibers spun through noncircular spinnerette holes, namely, rectangular holes, trilobal holes, and round holes with lugs. For the study, bench-scale apparatuses of wet spinning and melt spinning were used which had been constructed in connection with an earlier study by Han. In the wet-spinning experiment, the spin dope used was an aqueous solution of polyacrylonitrile (PAN) consisting of approximately 10% polymer and 40% sodium thiocyanate (NaSCN), and the spin dope was spun into aqueous solutions of NaSCN. In the melt-spinning experiment, polystyrene was used. The variables investigated were: size and shape of the spinnerette hole, coagulating bath concentration, throughput rate, and jet stretch. It has been found in wet spinning that, for a given shape of spinnerette hole, the fiber shape is most strongly affected by jet stretch and relatively little by the bath concentration and throughput rate. Also determined in the wet-spinning experiment was the maximum jet stretch at which thread breakage occurs. It has been found that the maximum jet stretch decreases as bath concentration is increased.

Anion exchange studies on lead(II) and thallium(I) thiocyanate complex systems

The distributions of Pb II, Tl I and I − between the strongly basic anion exchange resin Amberlite CG-400 and aqueous solutions of NaSCN and KSCN, were investigated. A secondary cation effect was observed to take place. Extending the related anion exchange theory, the complexes Pb(CNS 4 2− and Tl(CNS) 2 − were determined to be the species predominating in the resin phase. The distribution curves corrected for the invasion of the resin by the supporting electrolyte were then calculated, and the formation in the solution phase of the species Pb(CNS) n 2− n ( n ranging from 0 to 6) and Tl(CNS) n 1− n ( n ranging from 0 to 4) was inferred as a function of the ligand activity in solution ([KSCN] ranging from about 4×10 −2 to 5·5). The structures of the above aqueous systems, obtained by anion exchange, reasonably agree with those previously determined with other techniques. The overall effective anion exchange stability constants for Tl(CNS) n 1− n were calculated (log β 1 ∗=0·46 ; log β 2 ∗=0·92 ; log β 3 ∗=0·30 ; log β 1=0·40).