Measurement and correlation of the solubility of genistin in eleven organic solvents from T = (283.2 to 323.2) K

The solubilities of genistin in pure solvents including tetrahydrofuran, acetone, ethyl acetate, acetonitrile, isopropanol, n-butyl alcohol, methanol, cyclohexane, n-hexane, chloroform and ethanol were determined by the high performance liquid chromatography (HPLC) analysis method at T = (283.2, 293.2, 303.2, 313.2 and 323.2) K. The fusion enthalpy of genistin was estimated by the group contribution method. The solubility data of genistin were correlated by the simplified thermodynamic model, the modified Apelblat model, λh model and NRTL (Non-Random Two-Liquid) model. The calculated values by all models were in good agreement with the experimental values and however, the NRTL model could give better correlation results than other three models.     

Solubility of Xanthene in Organic Nonelectrolyte Solvents: Comparison of Observed Versus Predicted Values Based Upon Mobile Order Theory

Experimental solubilities are reported at 25.0°C for xanthene dissolved in 34 different organic nonelectrolyte solvents containing ether-, chloro-, hydroxy-, cyano and t -butyl-functional groups. Results of these measurements are used to test the applications and limitations of expressions derived from Mobile Order theory. For the 27 solvents for which predictions could be made computations show that Mobile order theory does provide fairly reasonable estimates of the saturation mole fraction solubilities. Average absolute deviation between predicted and observed values is 71.4%.     

高压下氮气在正庚烷-正辛烷混合溶剂中的溶解度研究

Solubilities of nitrogen in binary mixtures of n-octane and n-heptane have been measured at temperatures from 20 to 70 ℃ and pressures up to 130 atm using a precision gas-liquid solubility apparatus. Experimental results can be expressed by the following equation Inx_(N_2)=A+BP_(N_2)+CP_(N_2)~2+DInP From the results obtained, the partial molar volume of dissolved nitrogen and the Henry's Law constants have also been calculated.     

高压下氮气在正庚烷-正辛烷混合溶剂中的溶解度研究

高压下气体在混合溶剂中溶解度的测定与研究,无论在理论研究或是实际应用方面均具有重要的意义。但由于进行这类研究,特别是在升温升压下,费时,昂贵和有一定难度,目前这方面的数据十分缺乏。作为本实验室研究系列之一部份,本文将报导文献中尚未见发表的氮气在正庚烷-正辛烷混合溶剂中的溶解度研究结果。实验部份1.试剂氮气纯度99.999%,由北京氧气厂提供;正庚烷,正辛烷由北京化工厂产分析纯试剂,本实验室又进一步精馏纯化。纯化后的试剂用气相色谱分析其纯度高于99.4%.混合溶剂的组成用重量法配制。     

在电解质溶液中测定非电解质溶解度的新方法

提出了一种可以同时测定电解质溶液中非电解质的溶解度和饱和溶液水活度的新方法。该法把等压平衡与传统化学分析统一起来,其优点是：（1）将多元饱和溶液中非电解质溶解度的测定转变为共存离子的溶度测定,避开了对非电解质难于进行精确化学分析的难题;（2）可以同时确定所测饱和体系的水活度。用该法测定了NaCl和KCl溶液中甘露醇的溶解度并与文献值进行了比较,结果表明二者符合得很好。     

Solubility of the Pesticide Monuron in Organic Nonelectrolyte Solvents. Comparison of Observed Versus Predicted Values Based upon Mobile Order Theory

Experimental solubilities are reported at 25.0°C for monuron (also called 3-(4-chlorophenyl)-1,1-dimethyl urea) dissolved in 18 different organic nonelectrolyte solvents containing ether-, chloro-, hydroxy-, ester, methyl- and t -butyl-functional groups. Results of these measurements, combined with published literature data, are used to test the applications and limitations of expressions derived from Mobile Order theory. For the 21 nonalcoholic solvents for which predictions could be made computations show that Mobile Order theory does provide fairly reasonable estimates of the saturation mole fraction solubilities. Average absolute deviation between predicted and observed values is 48.4%. Monuron solubilities in the alcohol solvents are used to calculate stability constants for presumed solute-solvent hydrogen bonds that are believed to occur in solution.     

Uncharged Co(lll) Complexes: Transfer Chemical Potentials and Base Hydrolysis in Water-Methanol Mixtures

Solubilities are reported for three Co(III) complexes of 2-aminophenol, 2-amino-4-nitrophenol and 6-amino-2,4-dimethylphenol. Transfer chemical potentials have been derived from appropriate solubility measurements in aqueous methanol. The trends in transfer chemical potentials are discussed in terms of the nature of the coordinated ligands and are compared with those for selected of other inorganic Co(III) complex ions. The kinetics of base hydrolysis of Co(III) complexes in aqueous methanol solutions are described and the change in the activation barrier δ_mΔG^≠ is determined. Solvent effects on reactivity trends are analysed into initial state and transition state components. The small decrease in the rate constant, with increasing proportion of methanol, is ascribed to a greater effect of solvent on the initial state.     

Solubilities and Ksp Values of the Less Soluble Anion Salts of “Nitron” (1,4-Diphenyl-3-anilino-1,2,4-triazoline)

Abstract

The solubilities and K_sp values at 25°C for the following anion salts of nitron are reported: VO₄ ⁼, Cro₄ ⁼, Cr₂O₇ ⁼,WO₄ ⁼, MoO₄ ⁼, BF₄ ^?, NO₃ ^?, NO₂ ^?, SeO₃ ⁼, S₂O₈ ⁼, SCN^?, Fe(CN)₆ ^?3, Fe(CN)₆ ^?4, Fe(CN)₅NO⁼, I^?, IO₄ ^?, CIO₃ ^?, CIO₄ ^?, BrO₃ ^?, and picrate^?. A total of 58 anions were tested.     

The physicochemical properties and solubility of pharmaceuticals – Methyl xanthines

The aim of this study was to evaluate the physio-chemical properties and solubility of three pharmaceuticals (Phs): theophylline, 7-(β-hydroxyethyl) theophylline, and theobromine in binary systems in different solvents. The solvents used were water, ethanol, and 1-octanol. Score of the solubility of these substances is being important for their dissolution effect inside the cell, the transportation by body fluids and the penetration possibility of lipid membranes.The Phs were classified to the group of methyl xanthines, which contain purine in their structure. Although they are mainly obtained via chemical synthesis, they can be also found in natural ingredients such as cocoa beans and tea leaves. These drugs are mainly acting on the central nervous system but are also used in the treatment of asthma or blood vessels.Solubility of 7 (β-hydroxyethyl) theophylline and theophylline were tested using synthetic method. In case of theobromine, which solubility is very small in the solvents noted, the spectrophotometric method has been used to measure its solubility. After designating phase diagrams of each of the solubility in the bipolar system, the experimental points have been correlated with the equations: Wilson, NRTL, UNIQUAC. Results show that theophylline and its derivatives show the best solubility from all tested Phs.Another method also used during this study was the differential scanning calorimetry (DSC), which allowed designation of the thermal properties of Phs. The fusion temperature and the enthalpy of melting were measured. Unfortunately, it was not possible to determine the fusion temperature and enthalpy of melting of theobromine, because of the decomposition of Ph at high temperature.The important property tested was the constant acidity, to this end, the spectrophotometric method of Bates–Schwarzenbach was used. Unfortunately, with this method it was not possible to determine the value of pK_a 7-(β-hydroxyethyl) theophylline. For other Phs, these values do not differ significantly from those proposed in the literature.Both awareness and knowledge of values of the drug pK_a and solubility are important in Phs production. This allows the selection of a suitable solvent and allows estimation of the correct dose and its capacity to absorb in human body.     

Development of Abraham model correlations for solvation characteristics of linear alcohols

Data have been compiled from the published literature on the partition coefficients of solutes and vapors into the anhydrous linear alcohols (methanol through 1-heptanol, and 1-decanol) from both water and from the gas phase. The logarithms of the water-to-alcohol partition coefficients (log P) and gas-to-alcohol partition coefficients (log K) were correlated with the Abraham solvation parameter model. The derived correlations described the observed log P and log K values to within average standard deviations of 0.14 and 0.12 log units, respectively. The predictive abilities of the each correlation were assessed by dividing databases into a separate training set and test set.