Volumetric, rheological, and optical properties of Na-alkylsulfonates aqueous solutions at 29°C

Present paper reports density, relative viscosity and refractive index of sodium salt of 1-heptanesulfonic acid and 1-octanesulfonic acid at 29°C. Density data has been fitted to Masson empirical relation and limiting apparent molar volumes were evaluated. Viscosity A and B coefficients characterizing ion-ion and ion-solvent interactions have been evaluated by fitting viscosity data in Jone-Doles equation. Experimental and calculated properties support the strong ion-solvent interactions in solution.     

Temperature dependence of apparent molar volumes and viscosity B-coefficients of amino acids in aqueous potassium thiocyanate solutions from 15 to 35°C

Precise density and viscosity data at 15, 25 and 35°C for solutions of glycine, DL-alanine, L-threonine, -alanine, -aminobutyric acid and -aminocaproic acid in water and in (1m, 3m, 5m) aqueous potassium thiocyanate were measured and the limiting apparent molar volumes V ^o and the B-coefficients calculated. The V ^o and B values were split into the contributions from the NH ₃ ⁺ ,COO^– and CH₂ groups. These data are rationalized on the basis of hydrophillic and hydrophobic interactions between the various groups present in these solutions.Abstracted from the Ph.D Thesis of R. K. Goyal, University of Delhi, 1990.     

Structure and properties of ionic fullerene complex Co(+)(dppe)2·(C60˙-)·(C6H4Cl2)2: distortion of the ordered fullerene cage of C60˙- radical anions

New ionic complex {Co(+)(dppe)(2)}·(C(60)˙(-))·(C(6)H(4)Cl(2))(2) (1) was obtained by the reduction of a Co(dppe)Br(2) and C(60) mixture by TDAE in o-dichlorobenzene followed by precipitation of crystals by hexane. Optical and EPR spectra of 1 indicated the formation of C(60)˙(-) radical anions and diamagnetic Co(+)(dppe)(2) cations. The structure of 1 solved at 100(2) K involves chains of C(60)˙(-) arranged along the lattice a-axis with a center-to-center distance of 10.271 ?. The chains are separated by bulky Co(+)(dppe)(2) cations and solvent molecules. All components of 1 are well ordered allowing the distortion of the C(60)˙(-) radical anion to be analyzed. An elongation of the C(60)˙(-) sphere by 0.0254(2) was found. It is essentially smaller than those in the salts (Cp*(2)Ni(+))·(C(60)˙(-))·CS(2) and (PPN(+))(2)·(C(60)(2-)) with greater distortion of the fullerene cage. The calculation of the electronic structure of fullerene by the extended Hückel method showed slight splitting of the C(60) LUMO, due to the distortion, by three levels. Two levels are located 180 and 710 cm(-1) higher than the ground level. The averaged 6-6 and 5-6 bonds in C(60)˙(-) with lengths of 1.397(2) and 1.449(2) ? are close to those determined for the C(60)(2-) dianions in (PPN(+))(2)·(C(60)(2-)), but are slightly longer and shorter, respectively, than the length of these bonds in neutral C(60).     

Concentration dependences of the density, viscosity, and refraction index of Cu(NO3)2 · 3H2O solutions in DMSO at 298 K

Physicochemical properties (density, dynamic viscosity, refraction index) of the DMSO-Cu(NO₃)₂ · 3H₂O system are studied in the concentration range of 0.01–2 M at 298 K. The refraction index of a solution of copper(II) nitrate in dimethylsulfoxide (DMSO) is measured at 288–318 K. The excess and partial molar volumes of the solvent and dissolved substance are calculated analytically.     

Volumetric,rheological, and optical properties of hydroxylamine hydrochloride aqueous solutions containing NaCl,KCl, and NH4Cl at 30°C

Densities, viscosities, and refractive indices of aqueous solutions of hydroxylamine hydrochloride containing 0.05, 0.10, and 0.15 mol/dm³ NaCl, KCl, and NH₄Cl were measured at different concentrations of hydroxylamine hydrochloride at 30°C. Viscosity coefficients A and B representing ion-ion and ion-solvent interactions were determined from Jones-Dole equation. Experimental properties and viscosity coefficients have been interpreted in terms of ion-ion and ion-solvent interactions. Ion-solvent interactions were found to be dominating over the ion-ion interactions in studied systems.     

Formation of a new adduct based on fullerene tris-malonate samarium salt С60–[C60(=C(COO)2)3]Sm2

Gram quantities of a new adduct based on light fullerene tris-malonate samarium salt С₆₀ [C₆₀(=C(COO)₂)₃]Sm₂ are obtained via the reaction of ion exchange. The obtained adduct is studied by means of electron and infrared spectroscopy, X-ray and elemental analysis, electron microscopy, and thermogravimetry. The polythermal solubility of [C₆₀(=C(COO)₂)₃]Sm₂ in water is determined in ampoules via saturation within 20–70°C. The composition of crystalline hydrate [C₆₀(=C(COO)₂)₃]Sm₂ · 36Н₂О, which exists in equilibrium with the saturated solution, is estimated.

     

Thermodynamic properties of transition metals in aqueous solution. 2. The enthalpies of mixing of aqueous solutions of CoCl2, CuCl2, and MnCl2 with NaCl at varying ionic strength at 25°C

Enthalpies of mixing (_m H) aqueous solutions of CoCl₂, CuCl₂, and MnCl₂ with NaCl solutions were measured at constant ionic strengths of 0.5, 1.0, and 3.0 molal at 25°C. The excess enthalpy equations of Pitzer were then fit to the resulting _m H data. The resulting parameters are the temperature derivatives of the activity coefficient mixing parameters in the Pitzer system. The heat of mixing data for CoCl₂ and CuCl₂ were in agreement with earlier isomolal results by other workers.     

Preparation and Raman spectra of Ca(NO2)2·H2O,Ca(NO2)2 and Mg(NO2)2·H2O

The above named salts have been prepared from aqueous solutions of the pure nitrates. Distinct compounds Ca(NO₂)₂·H₂O and Ca(NO₂)₂ which are free of nitrate impurity have been characterized by their Raman spectra. The hydrated salt appears to contain four crystallographically non-equivalent nitrate groups. A distinct hydrate of magnesium formulated as Mg(NO₂)₂·H₂O can also be prepared and characterized by Raman spectroscopy but this sample always contained significant nitrate impurity.     

Laser flash photolysis of fullerols of C_(60) and of C_(70) in aqueous solutions

Ｓｉｎｃｅｇｒａｍｑｕａｎｔｉｔｉｅｓｏｆｆｕｌｌｅｒｅｎｅｓｗｅｒｅｓｅｐａｒａｔｅｄｆｒｏｍｃａｒｂｏｎｓｏｏｔｓ,ｍａｎｙｓｔｕｄｉｅｓｈａｖｅｂｅｅｎｔｒｉｇｇｅｒｅｄｏｎｔｈｅｉｒｓｔｒｕｃｔｕｒｅｓ,ｐｒｏｐｅｒｔｉｅｓａｎｄｒｅａｃｔｉｏｎｓ.Ａｓｆｕｌｌｅｒｅｎｅｓｃａｎｐｒｏｄｕｃｅｖｅｒｙｈｉｇｈｑｕａｎｔｕｍｙｉｅｌｄｓｏｆｓｉｎｇｌｅｔｏｘｙｇｅｎｗｈｉｌｅｅｘｃｉｔｅｄｂｙｌｉｇｈｔ,ｍｏｒｅｉｎｔｅｒｅｓｔｈａｓｂｅｅｎｆｏｃｕｓｅｄｏｎｔｈｅｅｘａｍｉｎａｔｉｏｎｏｆｔ…     

Molecular complex of C60 fullerene with an organic π-donor,bis(methylenedithiotetrathiafulvalene): synthesis,crystal structures,and properties

A new molecular complex based on [60]fullerene, namely, (BMDT-TTF)·C₆₀·2CS₂ (1) (where BMDT-TTF is bis(methylenedithiotetrathiafulvalene)) was synthesized. The molecular and crystal structures of 1 were established by X-ray diffraction analysis. Complex 1 has a layered structure, layers of C₆₀ molecules alternating with those formed by BMDT-TTF molecules and CS₂ molecules located between them. In complex 1, there are short contacts between C₆₀ and the donor molecules, which results in a changed BMDT-TTF geometry. The donor molecules in 1 form in addition short S...S contacts. The data of IR spectroscopy indicate that the charge transfer to the fullerene molecule is insignificant if at all present. The conductivity of a single crystal of 1 measured at 20 °C using a four-contact method is 2·10^–5 ( cm)^–1.     

Long-term γ-radiolysis kinetics of NO3(-) and NO2(-) solutions

Radiolysis kinetics in NO(3)(-) and NO(2)(-) solutions during γ-irradiation were studied at an absorbed dose rate of 2.1 Gy·s(-1) at room temperature. Air- or argon-saturated nitrate or nitrite solutions at pH 6.0 and 10.6 were irradiated, and the aqueous concentrations of molecular water decomposition products, H(2) and H(2)O(2), and the variation in the concentrations of NO(3)(-) and NO(2)(-) were measured as a function of irradiation time. The experimental data were compared with computer simulations using a comprehensive radiolysis kinetic model to aid in interpretation of the experimental results. The effect of nitrate and nitrite, present at concentrations below 10(-3) M, on water radiolysis processes occurs through reactions with the radical species generated by water radiolysis, (?)e(aq)(-), (?)O(2)(-), and (?)OH. The changes in H(2) and H(2)O(2) concentrations observed in the presence of nitrate and nitrite under a variety of conditions can be explained by a reduction in the radical concentrations. The kinetic analysis shows that the main loss pathway for H(2) is the reaction with (?)OH and the main loss pathways for H(2)O(2) are reactions with (?)e(aq)(-) and (?)OH. Nitrate and nitrite compete for the radicals leading to an increase in the concentrations of H(2) and H(2)O(2). Post-irradiation measurements of H(2), H(2)O(2), NO(2)(-) and NO(3)(-) concentrations can be used to calculate the radical concentrations and provide information on the redox conditions of the irradiated aqueous solutions.     

The volumes of mixing of aqueous solutions of CdCl2, CuCl2, MnCl2, and ZnCl2 with HCl at varying ionic strength at 25°C

The densities of mixtures of aqueous solutions of hydrochloric acid with solutions of cadmium chloride, copper chloride, manganese chloride, and zinc chloride have been measured at constant ionic strengths of 1.0 and 3.0 mol-kg^–1 at 25°C. The density data were used to determine the volumes of mixing (V _m ). The volume of mixing equations of Pitzer were then fit to the resulting V _m data to obtain the Pitzer parameters _V ^MN and _V ^MNX , which are the pressure derivatives of the free energy equation parameters.     

Apparent molar and partial molar volumes of aqueous ceric ammonium nitrate solutions at 20, 25, 30, and 35°C

Present paper reports the measured densities (ρ) and refractive indices (n _D) of aqueous solutions of ceric ammonium nitrate (CAN) at 20, 25, 30, and 35°C in different concentrations of solution. Apparent molar volumes (φ_v) have been calculated from the density data at different temperatures and fitted to Massons relation to get limiting partial molar volumes (? _v ⁰ ) of CAN. Refractive index data were fitted to linear dependence over concentration of solutions and values of constant K and n _D ⁰ for different temperatures were evaluated. Specific refractions (R _D) of solutions were calculated from the refractive index and density data. Concentration and temperature effects on experimental and derived properties have been discussed in terms of structural interactions.     

Syntheses,crystal structures and antibacterial activities of [Cu2(C11H11NO5S)2(H2O)4] · 5H2O and [Ni2(C11H11NO5S)2(H2O)4] · 2H2O

The binuclear complexes [Cu₂L₂(H₂O)₄] · 5H₂O (1) and [Ni₂L₂(H₂O)₄] · 2H₂O (2) (where L = C₁₁H₁₁NO₅S, H ₂ L = 2-[(3-formyl-5-methyl-2-hydroxy-benzylidene)-amino]ethanesulfonic acid) have been synthesized and characterized by IR, elemental analysis and X-ray diffraction. The crystals belong to the monoclinic system, space group P2₁/c. Complex 1: a = 16.8902(12), b = 11.2829(6), c = 17.4249(11) Å; β = 106.709(4)°; S = 1.131; V = 3180.5(3) ų; Z = 4; D _Calcd = 1.729 g cm^?3; F(000) = 1712; μ = 1.554 mm^?1; R ₁ = 0.0519, wR ₂ = 0.1349; complex 2: a = 11.399(2), b = 19.985(3), c = 7.3694(10) Å; β = 108.664(7)°; S = 1.157; V = 1590.6(4) ų; Z = 2; D _Calcd = 1.604 g cm^?3; F(000) = 800; μ = 1.388 mm^?1; R ₁ = 0.1859, wR ₂ = 0.4346. The geometry around each metal(II) center can be described as slightly distorted octahedral. Water-sulfonic clusters and (H₂O)₄ water clusters can be observed for 1 from the crystal packing diagram, while cavity and offset face-to-face π–π stacking can be observed for 2. The complexes have been tested for the antibacterial activities which show antibacterial activities of 1 for β-hemolytic streptococcus, Staphylococcus aureus and Escherichia coli, and the antibacterial activity of 2 only for β-hemolytic streptococcus.     

Synthesis,crystal structure,and luminescence properties of [TbGd(NAA)6(phen)2] and [Tb2(NNA)6(phen)2] · 2C3H7NO

Lanthanide(III) heteronuclear and binuclear complexes [TbGd(NAA)₆(phen)₂] (1) and [Tb₂(NAA)₆(phen)₂] · 2C₃H₇NO (2) (NAA = 1-naphthylacetic acid, phen = 1,10-phenanthroline) were prepared and their crystal structures were determined. In 1 and 2, each lanthanide is nine-coordinate by two bidentate-bridging and two tridentate chelating-bridging carboxylate groups, one bidentate chelating carboxylate and one phen molecule in a distorted monocapped square antiprism. The solid-state luminescence behavior and the antibacterial activities were studied. Complexes 1 and 2 exhibited characteristic emission of Tb(III) ion ⁵D₄ → ⁷F_J (J = 6–0) under UV radiation at room temperature. A main excitation peak (359 nm) of 2 appears under red emission of 615 nm. By contrast, all emission peak intensities of 1 were enhanced by addition of gadolinium(III), and the 545 nm band is much stronger than the 615 nm band, attributed to, under perturbation of the ligand field, the probability of ⁵D₄ → ⁷F₃ transition of Tb(III) was greatly enhanced in 2. Because of perturbation of the ligand field by addition of gadolinium(III), the probability of ⁵D₄ → ⁷F₅ transition of Tb(III) was greatly enhanced in 1 and green fluorescence was observed. The antibacterial activity showed that the two complexes were active against Escherichia coli, Staphylococcus aureus and Bacillus subtilis.     

Synthesis, characterization and standard molar enthalpy of formation of Nd(C7H5O3)2·(C9H6NO)

The complex from reaction of neodymium chloride six-hydrate with salicylic acid and 8-hydroxyquinoline, Nd(C₇H₅O₃)₂·(C₉H₆NO), was synthesized and characterized by IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [NdCl₃·6H₂O(s)], [2C₇H₆O₃(s)], [C₉H₇NO(s)] and [Nd(C₇H₅O₃)₂·(C₉H₆NO)(s)] in a mixed solvent of anhydrous ethanol, dimethyl formamide (DMF) and perchloric acid were determined by calorimetry at 298.15 K. Based on Hess’ law, a new chemical cycle was designed, and the enthalpy change of the reaction

The solvent influence on some physicochemical properties of Cu(NO3)2·3H2O-(CH3)2SO solutions

The electrical conductance of Cu(NO₃)₂·3H₂O solutions (0.00886–2.82 mol L^?1) in dimethylsulfoxide at 288–318 K has been studied by conductometry.     

Densities and apparent molar volumes for aqueous solutions of HNO3−UO2(NO3)2 at 298.15 K

In order to obtain the exact information of atomic number density in the ternary system of HNO₃−UO₂(NO₃)₂−H₂O, the densities were measured with an Anton-Paar DMA60/602 digital density meter thermostated at 298.15±0.01 K. The apparent molal volumes for the systems were calculated from the experimental data. The present measured apparent molar volumes have been fitted to the Pitzer ion-interaction model, which provides an adequate representation of the experimental data for mixed aqueous electrolyte solutions up to 6.2 mol/kg ionic strength. This fit yields θ ^V , and ψ ^V , which are the first derivatives with respect to pressure of the mixing interaction parameters for the excess free energy. With the mixing parameters θ ^V , and ψ ^V , the densities and apparent molar volumes of the ternary system studied in this work can be calculated with good accuracy, as shown by the standard deviations.