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Alkaline leaching is an effective method for dealing with arsenic-containing resources. Arsenic is dissolved in an alkaline solution in the form of arsenate, but the lack of relevant basic data has caused difficulties in the theoretical analysis during production and research. The dissolution behavior of arsenic in the solution was systematically studied in this paper. The solubility behavior of the self-made sodium arsenate in water and NaOH solution were measured. The research on sodium arsenate solution was carried out to obtain the quasi-solubility product using the Pitzer model, and the effect of temperature and NaOH concentration on the solubility and quasi-solubility product of sodium arsenate was clarified.

Magnetotactic bacteria have evolved complex subcellular machinery to construct linear chains of magnetite nanocrystals that allow the host cell to sense direction. Each mixed-valent iron nanoparticle is mineralized from soluble iron within a membrane-encapsulated vesicle termed the magnetosome, which serves as a specialized compartment that regulates the iron, redox, and pH environment of the growing mineral. To dissect the biological components that control this process, we have carried out a genetic and biochemical study of proteins proposed to function in iron mineralization. In this study, we show that the redox sites of c-type cytochromes of the Magnetospirillum magneticum AMB-1 magnetosome island, MamP and MamT, are essential to their physiological function and that ablation of one or both heme motifs leads to loss of function, suggesting that their ability to carry out redox chemistry in vivo is important. We also develop a method to heterologously express fully heme-loaded MamP from AMB-1 for in vitro biochemical studies, which show that its Fe(III)-Fe(II) redox couple is set at an unusual potential (-89 ± 11 mV) compared with other related cytochromes involved in iron reduction or oxidation. Despite its low reduction potential, it remains competent to oxidize Fe(II) to Fe(III) and mineralize iron to produce mixed-valent iron oxides. Finally, in vitro mineralization experiments suggest that Mms mineral-templating peptides from AMB-1 can modulate the iron redox chemistry of MamP.

• Musk xylene in ten organic solvents at temperatures ranging from 278.15 K to 313.15 K was measured. • Analysis of musk xylene by XRD. • Wilson model, NRTL model, Vant't Hoff equation, modified Apelblat equation, and λh equation are used to correlate the solubility of musk xylene in different solvents. • The mixed Gibbs energy, enthalpy and entropy were calculated according to Wilson model. In this study, isothermal saturation method was used to measure and correlate the solubility of musk xylene in ten organic solvents at temperatures ranging from 278.15 K to 313.15 K , including methanol, ethanol, isopropanol, n-butanol, cyclohexane, n-hexane, n-heptane, N,N-dimethylacetamide, ethyl acetate, tetrahydrofuran. The experimental results show that the solubility of musk xylene in the selected solvent increases with increasing temperature. The experimental data were correlated by five thermodynamic models, and the results showed that each model can give a satisfactory correlation. In addition, the three kinds of mixed thermodynamic properties of Gibbs energy, enthalpy and entropy of musk xylene in selected solvents were determined by solubility data and Wilson model. It can be seen that the dissolution of musk xylene in a given solvent is spontaneous and entropy driven. Exploring the solubility of musk xylene in different organic solvents and the thermodynamics of dissolution can not only provide basic data for industrial crystallization separation, but also have great significance for its own crystallization and theoretical research. [ABSTRACT FROM AUTHOR]

Abstract In this work, the solubility of 4-methylphthalic anhydride in eight organic solvents (methyl acetate, acetone, acetonitrile, toluene, butyl acetate, carbon tetrachloride, cyclohexane, n -heptane) was studied experimentally by the isothermal saturation method at temperatures from (278.15 to 318.15) K under atmosphere pressure. Results show that the solubility of 4-methylphthalic anhydride in selected organic solvents increases with rising of temperature. Molecular simulation between solute and solvent was applied to reveal the solubility behavior based on density functional theory (DFT). The experimental data were correlated by five thermodynamic models including Van't Hoff equation, modified Apelblat equation, λh equation, NRTL and Wilson model. All the models give acceptable results in regression analysis of the solubility data. The modified Apelblat equation provides a better correlation in this study. The mixing thermodynamic properties including Gibbs energy, enthalpy and entropy of 4-methylphthalic anhydride in selected solvents were also obtained. Outcome shows that the dissolution of 4-methylphthalic anhydride in selected solvents is spontaneous and entropy-driven. This study can provide fundamental data for the separating of 4-methylphthalic anhydride. Highlights • Solubility data for 4-methylphthalic anhydride in eight organic solvents were measured. • Molecular simulation was performed to reveal the solubility behavior. • Experimental solubility data were correlated by five thermodynamic models. • Mixing thermodynamic properties of 4-methylphthalic anhydride were calculated. [ABSTRACT FROM AUTHOR]

In this research, solid-liquid equilibrium for the ternary system (2-naphthaldehyde + o -phthalic anhydride + 1,4-dioxane) was measured at 283.15 K, 293.15 K and 303.15 K, respectively. Three isothermal phase diagrams of the system were plotted using the values of the experimental solubility. Pure 2-naphthaldehyde and o -phthalic anhydride were formed at (283.15, 293.15 and 303.15) K, and were determined by Schreinemaker’s wet residue method. The crystallization region of o -phthalic anhydride was found to be much larger than that of 2-naphthaldehyde at a certain temperature. The experimental solubility at multiple temperatures was correlated by the NRTL and Wilson models. The NRTL model was more accurate than the Wilson model in this system. The diagram of density versus component was also constructed. [ABSTRACT FROM AUTHOR]

Due to the lack of solubility data and thermodynamic parameters of vitamin K 3 in literature, we determined the solubility of vitamin K 3 in ten organic solvents including 1,2-dichloroethane, acetone, dichloromethane, cyclohexane, methanol, acetonitrile, methyl acetate, i-propanol, n-propanol and n-butanol in this research. It was found that the solubility of vitamin K 3 increases with the increasing temperature ranging from 278.15 to 313.15 K in all ten solvents. Four thermodynamic models regression illustrate that modified Apelblat is the most appropriate model to describe solubility of vitamin K 3 in these ten solvents; it provides 100 RAD value of 1.48 as well as 104 RMSD value of 5.94. To explain the change patterns of vitamin K 3 solubility in ten solvents, Hansen solubility parameters and DFT calculation were both applied. Outcomes indicate the solubility laws of vitamin K 3 not only depend on polarity and hydrogen bonded parameters but also rely on intermolecular interactions. On account of these, 1,2-dichloroethane and dichloromethane with stronger solute-solvent interactions show greater solubility than other solvents. Thermodynamic studies reveal that the dissolution of vitamin K 3 in these ten solvents is an entropy-driven and endothermic process. • Solubility data for vitamin K 3 in ten organic solvents were measured. • DFT and Hansen solubility parameters were performed to analyze the solubility behavior. • Experimental solubility data were correlated by five thermodynamic models. • Mixing thermodynamic properties were calculated. [ABSTRACT FROM AUTHOR]

• Isothermal saturation method was used to measure the solubility of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone in eight pure solvents and two binary solvents at temperatures ranging from 273.15 K to 308.15 K. • Analysis of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone by DSC and XRD. • Van't Hoff model, modified Apelblat model, NRTL model, Wilson model, Jouyban − Acree model, Sun model were used to correlate the solubility of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone. • Hansen solubility parameter was used to reveal the solubility behavior of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone. • The thermodynamic properties (Δ sol H°, Δ sol S°, Δ sol G°, %ξ H and %ξ TS) were discussed by van't Hoff equation. In this work, the solubility of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone was measured and correlated by isothermal saturation method in eight pure solvents (isopropyl alcohol, n -octanol, ethyl acetate, acetonitrile, ethanol, acetone, cyclohexane, methanol) and two binary solvents (isopropyl alcohol + ethyl acetate, ethanol + acetonitrile) at temperatures ranging from 273.15 K to 308.15 K. The results show that the solubility of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone in the selected solvent is positively correlated with temperature. The experimental solubility data were correlated by six thermodynamic models, including Van't Hoff equation, modified Apelblat equation, NRTL model, Wilson model, Jouyban − Acree model and Sun model. The values of RAD and RMSD showed that these models fit the solubility data well. Besides, Hansen solubility parameter was used to reveal the solubility behavior of 1-(4-tert-butyl-2,6-dimethylphenyl)ethenone. Finally, the thermodynamic propertie Δ sol H○, Δ sol S○, Δ sol G○, %ξ H and %ξ TS were calculated by van't Hoff equation. The results showed Δ sol H○, Δ sol G○, Δ sol S○, are all positive values, indicating that the dissolution process in selected solvents was entropy-driven and endothermic. [ABSTRACT FROM AUTHOR]

• Solubility data for 1-nitronaphthalene in twelve organic solvents were measured. • Intermolecular interactions and overall charge distribution of 1-nitronaphthalene were studied by HS and MEPS. • The data was well correlated by the Apelblat, van't Hoff, λh and Wilson models. • Molecular dynamic simulation was used to analyze the solute–solvent interactions. The solid–liquid equilibrium data of 1-nitronaphthalene in twelve pure solvents (methanol, ethanol, n -propanol, i-propanol, n -butanol, i-butanol, acetone, acetonitrile, dichloromethane, methyl acetate, ethyl acetate and cyclohexane) were systematically determined by isothermal saturation method in the temperatures ranging from 273.15 K to 308.15 K under atmospheric pressure (0.1 MPa). Molecular electrostatic potential surface and Hirshfeld surface analysis were applied to obtain the visual analysis of crystal structure and the overall charge distribution. The effect of solvent multiple physicochemical factors including polarity, hydrogen bond donor, hydrogen bond acceptor and cohesive energy density of solvent was explored to the solubility behavior. Then the experimental solubility data were correlated by the modified Apelblat equation, λ h equation, Van't Hoff equation and Wilson model, the ARD% was used to check the accuracy of the four equations and the modified Apelblat showed the best fitting. Furthermore, the mixing thermodynamic properties were calculated based on Wilson model, which indicates the dissolution of 1-nitronaphthalene is a spontaneous, endothermic and entropy-driving process. Finally, molecular dynamic simulations were employed to further analyze the dissolution behavior from solute-solvent interaction perspective. [ABSTRACT FROM AUTHOR]

• The solubility of Musk ambrette in single and binary solvents was determined. • The evaluation model for the relationship between solubility and temperature has been established. • The correspondence between solubility and the HSP, π , α , β , and CED of the solvents were discussed. • Molecular simulation was used to analyze the dissolution behavior of Musk ambrette. The solubility of Musk ambrette in i-propanol (IPA), i-butanol (IBA), n-heptane (HPT), n-hexane (HX), cyclohexane (CYH), methyl acetate (MAC), ethyl acetate (EAC), acetone (ACE), IPA + ACE at 278.15 K to 318.15 K was determined. The mole fraction solubility of Musk ambrette in pure IPA at the temperature of 298.15 K were found to be 0.9492 × 10-2 mol·mol−1. The difference is that the solubility of Musk ambrette in ACE reaches 0.2257 mol·mol−1, which is much higher than the solvent mentioned above. The strong intermolecular hydrogen bonding formed by IPA resulted in its lowest solvation capacity for Musk ambrette. In addition, to further investigate the solubility pattern of Musk ambrette, we used 8 models (Van't Hoff, modified Apelblat, Buchowski-Ksiazczak, Yaws, NRTL, Wilson, Jouyban-Acree and Sun model) to fit and obtain a general equation for solubility versus temperature. These results yielded a large amount of statistically significant data. Comparisons revealed that the modified Apelblat and Yaws equation showed the least deviation in forecasting solubility variations with temperature. Meanwhile, we proved that the dissolution of Musk ambrette is a heat-absorbing entropy increasing process by Van't Hoff equation calculation. Δ sol G o for the 12 solvents is in the following order: ACE < MAC < EAC < w = 0.2007 < w = 0.4025 < w = 0.6076 < CYH < w = 0.8070 < HPT < HX < IBA < IPA. Δ sol G o is smaller the easier it dissolves, which is consistent with the law of dissolution. Secondly, we performed thermal analysis and X-ray diffraction tests on Musk ambrette crystals prepared in different solvents, which showed that none of the several systems investigated led to the creation of new crystalline forms or solvatoids, further confirming the suitability of the solvents. Besides, we discuss the correspondence between solubility and the HSP, π , α , β , and CED of the solvents and thus tentatively confirm the significant influence of the solvent properties on solubility. The principle of similarity and compatibility is satisfied for most of the solvents. In particular, the CED values of the larger solvents were not favorable for the solubilization of Musk ambrette. We also analyzed the molecular surface electrostatic potential of Musk ambrette by visualization techniques. Finally, IPA and ACE and their binary solution systems were analyzed by molecular dynamics simulations. The effect of solvent intermolecular interactions on the solubilization pattern was discussed. It was further confirmed that weak interactions of solvent molecules contribute more to the dissolution of Musk ambrette. These findings suggest that the prediction of solvent solubility can be initially achieved by molecular simulation techniques. Undoubtedly, this study will furnish a valuable information for the purification of Musk ambrette. [ABSTRACT FROM AUTHOR]

• Solubility of 2,3-dichloropyridine in 14 pure solvents were measured. • Solubility modeling was realized by seven thermodynamic models. • Hansen solubility parameters were employed to explain solubility behaviors. • Solvent effect was studied by MEPs, Hirshfeld surface analysis and DFT calculation. • Thermodynamic properties were discussed by Van't Hoff equation. The solid–liquid equilibrium data of 2,3-dichloropyridine(23DCP) in 14 pure solvents were measured making use of the laser dynamic monitoring at 278.15/283.15/288.15 K − 313.15 K with 0.1 MPa. The findings of this study showed that the solubility increase of 23DCP in 14 pure solvents had a positive relation with temperature, and the solubility order was 1,4-dioxane > dichloromethane > n-butyl acetate > ethyl acetate > methyl acetate > acetonitrile > n-butanol > isobutyl alcohol > n-propanol > isopropanol > ethanol > cyclohexane > methanol > n-hexane. The solubility data of 23DCP was operated by seven models (Van't Hoff, modified Apelblat, λh, Yaws, NRTL, NRTL-SAC, Wilson) to correlate. And the average ARD values were 1.684 %,1.058 %, 1.031 %, 0.905 %, 0.937 %, 1.012 %, 2.062 % and the average 103RMSD values were 1.978, 1.396, 1.542, 1.221, 1.758, 1.658 and 1.883, respectively. In addition, Hansen solubility parameters were well evaluated to appraise the miscibility of 23DCP in 14 pure solvents. And the interactions between molecules were studied by means of molecular electrostatic potential surface, Hirshfeld surface analysis and density functional theory calculation. Finally, according to Van't Hoff equation, Δ sol G °, Δ sol H ° and Δ sol S ° of 23DCP in 14 pure solvents were got. Δ sol H ° and Δ sol S ° were bigger than zero, representing that this was a dissolution process of endothermic and entropy increase. [ABSTRACT FROM AUTHOR]

[Display omitted] • The solubility of musk amberette in single and binary solvents was determined. • Different thermodynamics models were used to correlate the solubility data. • Thermodynamic properties of musk amberette solution were calculated. • The effects of solvent properties and Hansen solubility parameters on solvent solubility were discussed. • Molecular simulation was used to analyze the dissolution behavior of musk amberette. The solubility of 4- tert -Butyl-2, 6-dinitro-3-methoxytoluene (musk amberette) in methanol, ethanol, n-propanol, n-butanol, acetonitrile, N, N-dimethylformamide, N, N-dimethylacetamide, tetrahydrofuran and methanol + tetrahydrofuran at 278.15 K to 318.15 K were determined. All measurement data obtained good results by merging Van't Hoff, modified Apelblat, λh , Yaws, NRTL, Wilson, Jouyban-Acree and Sun model. The deviation analysis between fitting values and experimental values indicates that the Yaws model was more effectively in fitting the solubility of musk amberette. In addition, the Δ sol H °, Δ sol G °, Δ sol S ° of musk amberette solution were discussed by Van't Hoff equation. Their fruits implied that the dissolution of musk amberette is found to be accompanied by heat absorption and entropy gain processes. This is consistent with the positive slope of the T- x 1 curve, which means that high temperature is advantage for the continued dissolution of musk amberette. In contrast, the presence of strong hydrogen bonds between alcohol solvents results in their lowest solubility for musk amberette. As an important task, the melting performance and crystal structure of musk amber were tested through instruments. The same characteristics exclude the presence of solvates or polymorphs. Finally, molecular visualization analysis was used to summarize the interatomic interactions within the crystal of musk amberette. The relationship between HSP, π , α , β , CED and their ability to dissolve musk amberette was discussed. It has been proven that high CED of the solvent is the main obstacle to the dissolution of musk amberette. The interaction between the O atom of musk amberette and hydroxyl H atom of alcohol in binary mixed solutions was obtained through molecular dynamics. Further, elucidated the relationship between mixed solvents and solubility. In summary, these studies will provide strong guidance for the upgrading of musk amberette production processes. [ABSTRACT FROM AUTHOR]

• Solubility of CDON in twelve organic solvents was determined. • The dissolution order of CDON was analyzed by solvent effect. • Experimental solubility data were correlated with five thermodynamic models. • CDON dissolution was observed to be endothermic and entropy-driven. The solubility of cyclododecanone (CDON) was determined in twelve solvents containing acetonitrile, acetone, toluene, ethyl acetate, cyclohexane, 1,2-dichloroethane, methanol, ethanol, n -propanol, i -propanol, n -butanol and i -butanol. The temperature range for the remaining solvents used in the experiment was 278.15–313.15 K, except for cyclohexane (283.15–313.15 K). The CDON solubility in solvents measured increased with growing temperature. The CDON solubility varies considerably in different solvents. Among the single solvents selected, CDON was most soluble in 1,2-dichloroethane and least in acetonitrile. The solubility in 1,2-dichloroethane is about 2–3 times higher than in acetonitrile. The carbonyl oxygen of CDON readily combines with alcoholic solvents to form hydrogen bonds. Hansen solubility parameters (HSP) and the physiochemical properties of the solvents explain the solvent effect in diverse solvents. To understand CDON dissolution, the electrostatic potential energy surfaces of CDON and the solute–solvent interactions were analyzed at the molecular level on the basis of density functional theory (DFT). Analysis of solvation effects revealed that variations in the CDON dissolution are influenced by a combination of factors rather than a single one. In addition, the Van't Hoff equation, modified Apelblat equation, Yaws equation, λh equation, Wilson model and Jouyban model were utilized to correlate the experimentally obtained value. The computational data show that the ARD (0.88%) and RMSD (0.24%) of Wilson model are the smallest among the selected equations with the best correlation. The apparent thermodynamic properties of CDON dissolution were further accounted for Van't Hoff equation, and the CDON dissolution was observed to be endothermic and entropy-driven. [ABSTRACT FROM AUTHOR]

In this study, isothermal saturation method was used to measure and correlate the solubility of musk ketone in twelve organic solvents at temperatures ranging from 278.15 K to 318.15 K, including methanol, ethanol, isopropanol, n-butanol, cyclohexane, n-hexane, n-heptane, N,N -dimethylformamide, N,N -dimethylacetamide, ethyl acetate, tetrahydrofuran and acetonitrile. The experimental results shown that the solubility of musk ketone in the selected solvent increases with increasing temperature. The experimental data were correlated by five thermodynamic models (Wilson model, NRTL model, Vant't Hoff equation, modified Apelblat equation and λh equation), all of the models can give a satisfactory correlation. In addition, mixed thermodynamic properties of Gibbs energy, enthalpy and entropy of musk ketone in selected solvents were calculated based on Wilson model. It can be seen that the dissolution of musk ketone in a given solvent is spontaneous and entropy driven. Exploring the solubility of musk ketone in different organic solvents and the thermodynamics of dissolution can provide basic data for industrial crystallization separation. • The solubility of musk ketone in twelve organic solvents was measured. • Analysis of musk ketone by DSC and XRD. • Vant't Hoff, modified Apelblat, λh, Wilson, and NRTL model were used to correlate the solubility data. • The mixed Gibbs energy, enthalpy and entropy were calculated according to Wilson model. [ABSTRACT FROM AUTHOR]

• Solubility data of 1,4-cyclohexanedione in ten pure solvents were measured. • Experimental data were correlated by five thermodynamic models. • Dissolution mechanism of 1,4-cyclohexanedione in ten pure solvents was investigated. • Thermodynamic properties were discussed by Wilson model. As an important raw material in industrial production, the solubility studies of 1,4-cyclohexanedione (14CHD) in organic solvents may be of assistance in improving crystallization efficiency and yield in industry. Therefore, this work deeply explored the dissolution behavior of 14CHD by using the isothermal saturation method, model fitting and density functional theory (DFT) calculation. Firstly, we selected ten pure organic solvents that are environmentally friendly to measure the solubility of 14CHD at the temperature range of 278.15 ∼ 313.15 K under standard atmospheric pressure. According to the measurement results, the solubility of 14CHD increases with temperature, and there are some differences among the solubility of 14CHD in various solvents. For instance, it has a highest solubility in acetonitrile (x 1 = 0.5331) at 313.15 K while has the lowest solubility (x 1 = 6.757 × 10-4) in cyclohexane at 283.15 K. Whereafter, the measured solubility data was correlated by Van't Hoff equation, modified Apelblat equation, λh model, Yaws model and Wilson model. Among them, Yaws model represents the most accurate fitting outcomes. At the same time, the study results of mixing thermodynamic properties on the basis of Wilson model suggest that the dissolution processes of 14CHD in ten organic solvents are entropy-driven and spontaneous. Afterwards, in order to explain the large difference in solubility of 14CHD in ten organic solvents, we found that the dissolution of 14CHD depends mostly on the polarity (π) and cohesive energy density (CED), viewed from the physicochemical factors of solvents. Furthermore, we further studied intermolecular interactions between 14CHD and ten solvents through molecular electrostatic potential surface (MEPS) analysis and DFT methods. Results display that alcoholic and non-alcoholic solvents molecules have different sites of action with 14CHD and the absolute values orders of interaction energies of alcoholic and non-alcoholic solvents are all consistent with corresponding solubility laws. The solvent–solute interaction plays an important role in the solubilities of 14CHD. [ABSTRACT FROM AUTHOR]