Speciation of 30 % tri-n-butyl phosphate solvent during extraction of nitric acid

Several solutions of 30 % TBP/n-dodecane were equilibrated with different concentrations of aqueous nitric acid solutions at 298.15 K at a phase ratio of unity. The resultant equilibrated aqueous and organic solutions were analyzed for acidity. A three-solvate model with molecular HNO₃ based mechanism was assumed for nitric acid extraction by TBP. With nonlinear chemometric methods, the coefficients were evaluated. With the set of optimized coefficients, derived on the basis of experiments reported in this work, the estimated solvate species and free-TBP species in the TBP containing organic phase were found to be in good agreement with the reported concentrations in the literature.     

Structural interaction leading to volumetric changes in aqueous solutions of nitrates of rubidium,cesium, strontium,yttrium, and gallium at different temperatures

Densities of the aqueous dilute solutions of rubidium, cesium, strontium, yttrium, and gallium nitrate were measured at different temperatures ranging from (293.15–343.15) K and atmospheric pressure. From these density values, the apparent molal volumes were calculated and fitted to Masson’s correlation and the temperature dependence was correlated by a second order polynomial. The apparent molal volumes at infinite dilution and experimental slopes have been interpreted in terms of ion–solvent and ion–ion interactions, respectively. The measurements include density as per ASTM D-4052, refractive index (nD²⁵) at sodium D line at 25 °C. Thermal isobaric expansibility was calculated and structure making and structure breaking behaviour of electrolytes were inferred from the sign of the second derivative of apparent molal volumes with respect to temperature at constant pressure. The experimental apparent molal volume was compared with the available literature value.     

Thermodynamic Modeling of Nitric Acid Speciation Using eUNIQUAC Activity Coefficient Model

Journal of Solution Chemistry - The speciation of nitric acid was modeled using eUNIQUAC activity coefficient model and the thermodynamic dissociation constant was estimated by solving the...     

Nickel‐Catalyzed α‐Carbonylalkylarylation of Vinylarenes: Expedient Access to γ,γ‐Diarylcarbonyl and Aryltetralone Derivatives

We report a Ni‐catalyzed regioselective α‐carbonylalkylarylation of vinylarenes with α‐halocarbonyl compounds and arylzinc reagents. The reaction works with primary, secondary, and tertiary α‐halocarbonyl molecules, and electronically varied arylzinc reagents. The reaction generates γ,γ‐diarylcarbonyl derivatives with α‐secondary, tertiary, and quaternary carbon centers. The products can be readily converted to aryltetralones, including a precursor to Zoloft, an antidepressant drug.     

Chemistry of organic eutectics: Phenanthrene — benzoic acid and phenanthrene — cinnamic acid systems

Solid-liquid equilibrium data for binary systems of phenanthrene with benzoic acid and cinnamic acid, expressed in the form of temperature-composition curves, show the formation of a simple eutectic in each case. Linear velocity of crystallisation (v), studied by capillary method at different undercoolings (ΔT), suggests the applicability of Hillig-Turnbull equation, v = u(ΔT) ⁿ, where u and n are constants depending on the nature of solidification. Data on heats of fusion of pure components and eutectics, determined by the DTA method, infer appreciable interaction among the components in the eutectic melts. To highlight the nature of interactions among the components forming the eutectic melt, the excess thermodynamic functions such as h^E, s^E, and g^E were computed. Microscopic studies reveal that the structure of eutectic is different from those of the parent components. Infrared spectra, recorded in the region, 4000 —625 cm⁻¹, indicate weak interactions among the components in the eutectic.     

Multispectroscopic DNA interaction and Docking studies

Two new water soluble oxovanadium(IV) complexes with formulae Na[VO(his)(met)SO₄] (1) and Na[VO(gly)(met)SO₄] (2), (gly=glycine his=histidine, and met=metformin) were synthesized and characterized by LCMS, UV‐Visible absorption, infrared spectra, magnetic moment, elemental analysis, thermal analysis and electronic spectral studies. The metal center was found in an octahedral geometry. DNA binding interaction of these complexes with CT DNA has been explored by UV‐Visible absorption, fluorescence, viscosity measurements and cleavage studies. Finally the binding of the complexes with CT‐DNA could be surface binding, mainly in the groove binding. The complexes were docked in to B‐DNA sequence, 5’(D*AP*CP*CP*GP*AP*CP*GP*TP*CP*GP*GP*T)‐3’ retrieved from protein data bank (PDB ID: 423D), using Discovery Studio 2.1 software.     

Blue phase III widening in CE6-dispersed surface-functionalised CdSe nanoparticles

The phase transition behaviour of the chiral liquid crystal CE6 doped with spherical surface-functionalised CdSe nanoparticles has been examined by means of high-resolution adiabatic scanning calorimetry and polarising microscopy. The addition of nanoparticles results in an essentially stabilised blue phase III. The phase diagram is displayed upon heating and cooling and the enthalpy changes involved in the conversion between the blue phases are determined. The dispersion of functionalised nanoparticles is prominent for the stabilisation of blue phase III, which is potentially useful for applications, especially if applied on liquid crystals that exhibit blue phases close to room temperature.