Solution Chemistry

Chromatographic retention data were measured for a wide range of organic solutes on 1-butyl-1methylpyrolidinium tris(pentafluoroethyl)trifluorophosphate, ([BMPyrr] + [FAP] -) and 1-butyl-1methylpyrrolidinium triflate, ([BMPyrr] + [Trif] -) and 1-methoxyethyl-1-methylmorpholinium tris(pentafluoroethyl)trifluorophosphate, ([MeoeMMorp] + [FAP] -), stationary phases at 323 K, 353 K and 383 K. The measured retention factors were combined with published infinite dilution activity coefficient and gas-to-water partition coefficient data to yield gas-to-anhydrous ionic liquid (IL) and water-to-anhydrous IL partition coefficients. The three sets of partition coefficients were analyzed using the Abraham model. The derived Abraham model correlations describe the observed gas-to-IL (log 10 K) and water-to-IL (log 10 P) partition coefficient data to within average standard deviations of about 0.11 and 0.15 log 10 units, respectively.

Chromatographic retention data were measured for a wide range of organic solutes on 1-butyl-1methylpyrolidinium tris(pentafluoroethyl)trifluorophosphate, ([BMPyrr] + [FAP] -) and 1-butyl-1methylpyrrolidinium triflate, ([BMPyrr] + [Trif] -) and 1-methoxyethyl-1-methylmorpholinium tris(pentafluoroethyl)trifluorophosphate, ([MeoeMMorp] + [FAP] -), stationary phases at 323 K, 353 K and 383 K. The measured retention factors were combined with published infinite dilution activity coefficient and gas-to-water partition coefficient data to yield gas-to-anhydrous ionic liquid (IL) and water-to-anhydrous IL partition coefficients. The three sets of partition coefficients were analyzed using the Abraham model. The derived Abraham model correlations describe the observed gas-to-IL (log 10 K) and water-to-IL (log 10 P) partition coefficient data to within average standard deviations of about 0.11 and 0.15 log 10 units, respectively.

Water-soluble coronenes, that form nanoparticles by self-association, work as new fluorescent materials by complexation with cucurbit[7]uril, as well as selective turn-on fluorogenic sensors for nitroaromatic explosives with remarkable selectivity, by using only water as solvent.

This IUPAC-NIST Solubility Data Series volume reviews experimentally determined solubility data for 33 nonsteroidal anti-inflammatory drugs (NSAIDs) dissolved in neat organic solvents and well-defined binary and ternary organic solvent mixtures retrieved from the published chemical and pharmaceutical literature covering the period from 1980 to the beginning of 2014. Except for aspirin (2-acetoxybenzoic acid) and salicylic acid (2-hydroxybenzoic acid), very little physical and chemical property data are available in the published literature for NSAIDs prior to 1980. Solubility data are compiled and critically reviewed for aclofenac, celecoxib, dexibuprofen, diclofenac,

The study of the diffusion of ferric ions in agar gel containing transition metal sulfates was carried out. The effect of gel concentration, electrolyte concentration and temperature on the diffusion of Fe 3+ ions in various transition metal sulfates was studied with a view to verify Wang's model of diffusion and the applicability of transition state theory to diffusion in a gel medium. The diffusion coefficients were measured using the zone diffusion technique. For a given concentration of electrolyte the activation energy (E) is found to decrease with an increase in the charge density of the cation of the supporting electrolyte and for a given system it is found to decrease with increasing electrolyte concentration in agreement with Wang's model. This observation is explained on the basis of the distortion in the water structure caused by ions and agar molecules. At a given electrolyte concentration the magnitude of the Arrhenius parameters, E and D o , is found to decrease with increasing gel concentration in agreement with the transition state theory of diffusion.

The study of the diffusion of ferric ions in agar gel containing transition metal sulfates was carried out. The effect of gel concentration, electrolyte concentration and temperature on the diffusion of Fe 3+ ions in various transition metal sulfates was studied with a view to verify Wang's model of diffusion and the applicability of transition state theory to diffusion in a gel medium. The diffusion coefficients were measured using the zone diffusion technique. For a given concentration of electrolyte the activation energy (E) is found to decrease with an increase in the charge density of the cation of the supporting electrolyte and for a given system it is found to decrease with increasing electrolyte concentration in agreement with Wang's model. This observation is explained on the basis of the distortion in the water structure caused by ions and agar molecules. At a given electrolyte concentration the magnitude of the Arrhenius parameters, E and D o , is found to decrease with increasing gel concentration in agreement with the transition state theory of diffusion.

In the partial wave treatment of electron-neutral atom collisions the calculation of converged cross-sections is greatly complicated by the large number ofangular momentum states which contribute. Methods of acceleratingthis convergence are discussed.

In this paper, a new Gibbs energy model is proposed to study the thermophysical properties of aqueous electrolyte solutions at various temperatures. The proposed model assumes that the electrolytes completely dissociate in solution. The model also has two temperature-independent adjustable parameters that were regressed using experimental values of the mean ionic activity coefficients (MIAC) for 87 electrolyte solutions at 298.15 K. Results from the proposed model for the MIAC were compared with those obtained from the E-Wilson, E-NRTL, Pitzer and the E-UNIQUAC models, and the adjustable model parameters were used directly to predict the osmotic coefficients at this temperature. The results showed that the proposed model can accurately correlate the MIAC and predict the osmotic coefficients of the aqueous electrolyte solutions better on the average than the other models studied in this work at 298.15 K. Also, the proposed model was examined to study the osmotic coefficient and vapor pressure for a number of aqueous electrolyte solutions at high temperatures. It should be stated that in order to calculate the osmotic coefficients for the electrolyte solutions, the regressed values of parameters obtained for the vapor pressure at high temperatures were used directly. The results obtained for the osmotic coefficients and vapor pressures of electrolyte solutions indicate that good agreement is attained between the experimental data and the results of the proposed model. In order to unequivocally compare the results, the same experimental data and same minimization procedure were used for all of the studied models.

The spectral characteristics of 2,4-dihydroxyazobenzene (DHAB, sudan orange G) and 4-hydroxyazobenzene (HAB) have been studied in various solvents, different hydrogen ion and β-cyclodextrin (β-CD) concentrations, and are compared with azobenzene (AB). The inclusion complexes of the above molecules with β-CD were analyzed by UVvis spectrometry, flourometry, FT-IR, 1 H NMR, SEM and DFT methods. The solvent study shows that only the azo form is present in DHAB and HAB molecules. The unusually large red shift observed in acidic solutions indicates both molecules exhibit azo-hydrazo tautomerization. In the β-CD solutions, the increase in fluorescence intensity and large bathochromic shift in the S 1 state indicates that DHAB and HAB form 2:2 inclusion complexes, whereas AB forms a 1:1 inclusion complex.

Vapor pressure data for solutions of various alkali metal and tetraalkylammonium salts in methanol at 25 ~ and NaI solutions in ethanol, x] < 0.75 are used to show the applicability of the HNC integral equation method to nonaqueous electrolyte solutions. Friedman's model of overlapping cospheres is used to express the non-electrostatic part of the ion-interaction potential. Data analysis is based on the Rasaiah-Friedman algorithm for the calculation of g § and g+_ functions. After conversion from Lewis-Randall to the McMillan-Mayer system the measured osmotic coefficients of all electrolyte solutions can be reproduced with the help of the calculated correlation functions.

Mixtures of sulfoxides with molecular solvents possess interesting physicalchemical properties and may have applications in chemical synthesis. Hereby we confirm and rationalize the previously reported excellent miscibility of diethyl sulfoxide (DESO) with methanol (MeOH). By performing a comprehensive potential energy surface investigation we identified a global minimum for each system and a significant number of local minima described at the hybrid density functional level of theory. A strong 0.18-nm-long hydrogen bond forming between the oxygen atom of DESO and the polarized hydrogen atom of MeOH was evidenced both via the structural and spectral analyses. Our results robustly explain negative deviations in the DESO-MeOH mixtures from ideal behavior and interpret the experimental observations with microscopic precision.

Freezing point lowerings of aqueous solutions of uranyl sulfate in the concentration range m < 0.40 mol-kg-1 and the activity and osmotic coefficients, which were calculated using the Pitzer equations for 2:2 electrolytes, are presented. Crystallization temperatures are reported for 0 to 13 molar nitric acid and 10-150 g uranium per liter uranyl nitrate-nitric acid-water solutions.

pK Values of carboxylic acids have been measured in mixtures water-organic solvent and confronted with the Born equation. Solubilities of benzoic acid have been measured. From the pK and solubilities found the ΔGt0(C6H5COO-) values have been calculated for various two-component solvents. The results agree with the idea that the ion transfer into another medium is affected not only by electrostatic, but also by non-electrostatic forces.

The viscosity of five [(0.27, 0.58, 0.92, 1.73, and 2.63) mol‚kg -1 ] binary aqueous SrCl 2 solutions has been measured with a capillary flow technique. Measurements were made at pressures up to 20 MPa. The range of temperature was (293 to 473) K. The total uncertainties in viscosity, pressure, temperature, and composition measurements were estimated to be less than 1.6 %, 0.05 %, 15 mK, and 0.02 %, respectively. The effects of temperature, pressure, and concentration on the viscosity of SrCl 2 (aq) solutions were studied. The temperature and pressure coefficients of the viscosity of SrCl 2 (aq) were studied as a function of concentration and temperature. The measured values of viscosity were compared with data, predictions, and correlations reported in the literature. The viscosity data were used to accurately calculate the physical meaning parameters (viscosity A and B coefficients) in the extended Jones-Dole equation for the relative viscosity (η/η 0 ). Various theoretical models [absolute rate theory, TTG (Tammann-Tait-Gibson) model, extended Einstein model] were used to accurately represent the measured values of viscosity. The values of hydrodynamic molar volume, V k (effective rigid molar volume of salt), were calculated using the present experimental viscosity data. The high-pressure viscosity measurements were used to test the predictive capability of the TTG model.

In this paper, a dielectric relaxation study on Bromobenzene (BB) - Diethylene Glycol Monomethyl Ether (DGME) binary mixtures has been carried out with varying concentrations at different temperatures in the frequency range between 10MHz-20GHz using time domain reflectometry (TDR) technique in reflection mode. Dielectric parameters viz. dielectric constant (e0), relaxation time (τ) were obtained from complex permittivity spectra e*(ω), using nonlinear least squares fit method. Using these parameters, thermodynamic parameters are determined. All the systems show a systematic change in dielectric parameters with temperature and concentration. The dielectric relaxation is use to estimate thermodynamic Parameters. Thermodynamic properties are helpful in accessing the states of dipoles under the influence of applied field.

The hydrolytic species of lanthanide ions, La 3? and Sm 3? , in water at I = 0.1 molÁdm -3 KCl ionic strength and temperatures of 298.15, 310.15 and 318.15 K were investigated by potentiometry. The hydrolytic species were modeled by the HySS simulation program. From the results, the hydrolytic species of each metal ion at different temperatures were calculated using the program HYPERQUAD2013. The hydrolysis constants (log 10 b) of [La(OH)] 2? and La(OH) 3 were calculated as -8.52 ± 0.46, -26.84 ± 0.48, and log 10 b values of [Sm(OH)] 2? , [Sm(OH) 2 ] ? , Sm(OH) 3 were calculated as -7.11 ± 0.21, -15.84 ± 0.25 and -23.44 ± 0.52 in aqueous media at 298.15 K, respectively. The dependence of the hydrolysis constants on the temperature allowed us to calculate the enthalpy, entropy, and Gibbs energy of hydrolysis values of each species.

The aim of this work is to describe the solubility of polycyclic aromatic hydrocarbons (PAHs) in subcritical water. To achieve this goal, first, a literature survey of the solubilities of PAHs in water and of naphthalene in mixtures of water and ethanol was made. Subsequently, the cubic plus association equation of state was used to describe the solubility of PAHs in the liquid phase. For accurate descriptions of the aqueous solubility of PAHs, the binary interaction parameters and cross-association volumes were regressed based on the experimental solubilities at atmospheric pressure. These regressed parameters are then used for subcritical water. Additionally, these parameters have been determined for the (naphthalene ? ethanol) binary system. These regressed parameters have then been applied to predict the solubility of naphthalene in (ethanol ? water) solutions. The results of the present model prove that it can be successfully applied for reproducing the solubilities of PAHs in the aqueous phase.

The aim of this work is to describe the solubility of polycyclic aromatic hydrocarbons (PAHs) in subcritical water. To achieve this goal, first, a literature survey of the solubilities of PAHs in water and of naphthalene in mixtures of water and ethanol was made. Subsequently, the cubic plus association equation of state was used to describe the solubility of PAHs in the liquid phase. For accurate descriptions of the aqueous solubility of PAHs, the binary interaction parameters and cross-association volumes were regressed based on the experimental solubilities at atmospheric pressure. These regressed parameters are then used for subcritical water. Additionally, these parameters have been determined for the (naphthalene ? ethanol) binary system. These regressed parameters have then been applied to predict the solubility of naphthalene in (ethanol ? water) solutions. The results of the present model prove that it can be successfully applied for reproducing the solubilities of PAHs in the aqueous phase.

The design of installations in the chemical industry requires knowledge of the thermodynamic properties of liquid mixtures. In the absence of experimental data, accurate predictive methods are needed. In this work, the refractive index and the surface tension are experimentally determined at different temperatures and atmospheric pressure, for the binary and ternary systems of benzyl alcohol, n-hexanol and water, less studied in the literature. Two models were developed for the correlation of excess surface tension with composition, normalized temperature and refractive index. The statistical processing of the experimental data with the multiple linear regression method allowed the development of a model for which, in the validation stage, the correlation coefficient was 0.9086 and the standard deviation was 4.36. With the best performing neural model, a correlation coefficient of 0.9727 and a standard deviation of 2.14 were obtained in the validation stage.

The measurements of ultrasonic velocity and density were made for the ternary mixtures of benzyl chloride and bromobenzene with o-cresol in a non-polar solvent, carbon tetrachloride at various concentrations for varying temperatures (30, 40, 50 °C) at a frequency of 2 MHz. Various ...

In this paper, a new Gibbs energy model is proposed to study the thermophysical properties of aqueous electrolyte solutions at various temperatures. The proposed model assumes that the electrolytes completely dissociate in solution. The model also has two temperature-independent adjustable parameters that were regressed using experimental values of the mean ionic activity coefficients (MIAC) for 87 electrolyte solutions at 298.15 K. Results from the proposed model for the MIAC were compared with those obtained from the E-Wilson, E-NRTL, Pitzer and the E-UNIQUAC models, and the adjustable model parameters were used directly to predict the osmotic coefficients at this temperature. The results showed that the proposed model can accurately correlate the MIAC and predict the osmotic coefficients of the aqueous electrolyte solutions better on the average than the other models studied in this work at 298.15 K. Also, the proposed model was examined to study the osmotic coefficient and vapor pressure for a number of aqueous electrolyte solutions at high temperatures. It should be stated that in order to calculate the osmotic coefficients for the electrolyte solutions, the regressed values of parameters obtained for the vapor pressure at high temperatures were used directly. The results obtained for the osmotic coefficients and vapor pressures of electrolyte solutions indicate that good agreement is attained between the experimental data and the results of the proposed model. In order to unequivocally compare the results, the same experimental data and same minimization procedure were used for all of the studied models.

Spectrophotometric studies of chloroform solutions of molecular iodine containing some thiophene derivatives are reported. The thermodynamic and electronlc spectral characteristics of 1 :1complexes formed between molecular iodine and some thiophene derivatives in chloroform have been determined. The formation constants (KCT) and extinction coefficients (€CT) of the thiophene-I, complexes have been determined by Liptay method. The ionization potentials (ID) of thiophene derivatives have been obtained from the energies of the charge transfer transitions (ECT) and are correlated with KCT and ECT. The linear Ielation between t:,H and LS indicates that the complex formation may be controlled not only by electronic factors but also by different steric requirements. ID of the donors as well as KCT and ECT of the complexes support Tt-----1&lt;* interaction between thiophenes and It with a conjugative contribution from the n-eledrons of the sulphur atom.

Densities, ρ, and speeds of sound, u, of 2-heptanone + aniline + N -methylaniline or + pyridine systems have been measured at (293.15, 298.15 and 303.15) K and atmospheric pressure using a vibrating tube densimeter and sound analyzer. The ρ and u values were used to calculate excess molar volumes, V E , and the excess functions at 298.15 K for the speed of sound, u E , the thermal expansion coefficient, α E p , and for the isentropic compressibility, κ E S . V E and κ E S are both negative and increase in the sequence: aniline < N -methylaniline < pyridine. In contrast, u E is positive and changes in the opposite way. The data suggest the existence of interactions between unlike molecules, which are much weaker in the pyridine solution. Aromatic amine-alkanone interactions are stronger in mixtures with acetone. The linear dependence of Rao's constant with concentration reveals that there is no complex formation in the investigated systems.

The solubility of the noble gases Ar, He, Ne, Kr, and Xe in pure water was measured from 298 to 561~ These data in turn were extrapolated to the eritieal point of water, thus providing a complete set of Henry's law constants from 274 to 647~ when combined with the existing literature data. Equations describing the behavior of the Henry's law constants over this temperature range are also given. The data do not confirm extrapolations of empirical correlations based on low-temperature solubility data.

An apparent molar volume ϕv of 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol in dilute aqueous solution has been particular for density measurements at 298.15 K. A restrictive apparent molar volumes ϕv˚ at infinite dilution of these compounds were investigated based on Masson's equation. Based on the Jone-Dole equation, A and B viscosity constants for four alcohols have been identified. This liquid offers resilient solute-solvent interaction. The modified Jone-Dole equation has also been employed with the experimental consequences using four liquids as solutes in dilute aqueous solutions.

Curculigosides A and B, two of the phyto-constituents of the medicinal plant Curculigo orchioides gatern, were isolated. The binding properties of these curculigosides with β-cyclodextrin, and their interaction with bovine serum albumin in free and β-cyclodextrincomplexed forms, were studied using fluorescence spectroscopy. The stoichiometry and binding constants of these complexes together with their binding modes are reported. Both of the curculigoside-cyclodextrin complexes are found to bind more weakly to the bovine serum albumin molecule than their free forms. The difference in the binding strengths of curculigoside A and curculigoside B with cyclodextrin makes a difference in their binding with bovine serum albumin.

Densities and viscosities have been measured for the binary mixtures of methanol with chlorobenzene and with bromobenzene from 293 K to 313 K over the complete composition range. Densities were used to compute the excess molar volume (V E m), for these binary systems. The results have been discussed in terms of molecular interactions. Furthermore, viscosity results were compared with a corresponding-states model. The average absolute deviation was found to be 1.9 %.

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The 17 O-NMR spin-lattice relaxation times (T 1) of water molecules in aqueous solutions of n-alkylsulfonate (C 1 to C 6) and arylsulfonic anions were determined as a function of concentration at 298 K. Values of the dynamic hydration number, n DHN (S −) = n − h (τ − c /τ 0 c − 1), were determined from the concentration dependence of T 1. The ratios (τ − c /τ 0 c) of the rotational correlation times (τ − c) of the water molecules around each sulfonate anion in the aqueous solutions to the rotational correlation time of pure water (τ 0 c) were obtained from the n DHN (S −) and the hydration number (n − h) results, which was calculated from the water accessible surface area (ASA) of the solute molecule. The τ − c /τ 0 c values for alkylsulfonate anions increase with increasing ASA in the homologous-series range of C 1 to C 4 , but then become approximately constant. This result shows that the water structures of hydrophobic hydration near large size alkyl groups are less ordered. The rotational motions of water molecules around an aromatic group are faster than those around an n-alkyl group with the same ASA. That is, the number of water-water hydrogen bonds in the hydration water of aromatic groups is smaller in comparison with the hydration water of an n-alkyl group having the same ASA. Hydrophobic hydration is strongly disturbed by a sulfonate group, which acts as a water structure breaker. The disturbance effect decreases in the following order:-SO − 3 >-NH + 3 > OH > NH 2. The partial molar volumes and viscosity B V coefficients for alkylsulfonate anions are linearly dependent on their n DHN (S −) values.

The 17 O-NMR spin-lattice relaxation times (T 1) of water molecules in aqueous solutions of n-alkylsulfonate (C 1 to C 6) and arylsulfonic anions were determined as a function of concentration at 298 K. Values of the dynamic hydration number, n DHN (S −) = n − h (τ − c /τ 0 c − 1), were determined from the concentration dependence of T 1. The ratios (τ − c /τ 0 c) of the rotational correlation times (τ − c) of the water molecules around each sulfonate anion in the aqueous solutions to the rotational correlation time of pure water (τ 0 c) were obtained from the n DHN (S −) and the hydration number (n − h) results, which was calculated from the water accessible surface area (ASA) of the solute molecule. The τ − c /τ 0 c values for alkylsulfonate anions increase with increasing ASA in the homologous-series range of C 1 to C 4 , but then become approximately constant. This result shows that the water structures of hydrophobic hydration near large size alkyl groups are less ordered. The rotational motions of water molecules around an aromatic group are faster than those around an n-alkyl group with the same ASA. That is, the number of water-water hydrogen bonds in the hydration water of aromatic groups is smaller in comparison with the hydration water of an n-alkyl group having the same ASA. Hydrophobic hydration is strongly disturbed by a sulfonate group, which acts as a water structure breaker. The disturbance effect decreases in the following order:-SO − 3 >-NH + 3 > OH > NH 2. The partial molar volumes and viscosity B V coefficients for alkylsulfonate anions are linearly dependent on their n DHN (S −) values.

An approach to analyzing stability of complexes in binary solvents based on the coordination model
of solvation is suggested. The equilibrium constants of substitution of solvent molecules in the coordination
sphere of the central ion and at ligand reaction centers, the composition of solvation sheaths, and the distribution
of solvato complexes in a mixed solvent were determined for the example of the Ag(I) complex with 3,6-dioxaoctane-
1,8-diamine in aqueous solutions of acetonitrile. The reasons for the extremal character of the dependence
of complex stability on the composition of the solvent and the role played by selective solvation of the
reagents were established. In analyzing solvent effects, it is expedient to distinguish between reagent solvation
centers that participate and do not participate in complex formation.

The rheological behavior of hydrophobically modified hydroxyethyl cellulose (HMHEC), an associative thickener, was studied and compared with that of hydrophobically modified ethoxylated urethanes (HEURs) and nonassociative celluloses. In contrast to HEURs, a simple Maxwell model does not fit the linear viscoelastic behavior of HMHEC. Differences are attributed to the stiffness and comb structure of HMHEC. A generalized Maxwell model with a logarithmic distribution of relaxation times is proposed, and another parameter that includes Rouse-like relaxation is added to fit behavior at high frequencies. Four parameters are needed to describe HMHEC viscoelasticity: a mean relaxation time, λM; its corresponding standard deviation, σ; a plateau modulus, GN; and a viscosity at infinite frequency, η∞. Satisfactory fitting is obtained for all concentrations and temperatures in the range of frequencies studied. The sharp increase of GN with concentration indicates loop-to-bridge transitions. Te...

Synthesis and characterization of Et 3 PAuI:………………………………………………… ……………………………………….2 LogP determination…………………………………………………..…………………………………………………………….………………2 Apoptosis plots………………………………………………………………………………………………………………………………….……3 Cell death and caspase activity…………………………………………………………………………………………………………………3 Cell growth inhibition studies (Sulforhodamine B assay)…………………………………………………………………………4 Tolerability studies………………………………………………………………………………………………………………………………….4 Biodistribution studies…………………………………………………………………………………………………………………………….4 In vivo anticancer activity evaluation xenograft subcutaneous models plots…………………………………………..7 NMR stability …………………………………………………………………………………………………………………………………………8

The solubility of D,L-phenylalanine in aqueous sodium chloride and D,L-serine in aqueous sodium nitrate at 5 K intervals from 288.15 to 308.15 K are reported in the present study. The standard Gibbs energies (DG 0 t ðiÞ) and entropies (DS 0 t ðiÞ) of transfer were evaluated at 298.15 K from the solubility of these amino acids. The solubilities were measured by an 'analytical formol titrimetry' method. The chemical parts of the Gibbs energies (DG 0 t;ch ðiÞ) and entropies (TDS 0 t;ch ðiÞ) of transfer of the amino acids were calculated by subtracting the cavity effects and dipole-dipole interaction effects from the total standard transfer energies. The characteristics of the solubility and solvation thermodynamics of amino acids in such aqueous electrolytes solvent systems were studied and discussed in the light of hydrogen bonding, and hydrophilic and hydrophobic interactions.

The 1:1 ion-pair formation constants (K IP ) of tetraalkylammonium (Me 4 N + , Et 4 N + , Pr 4 N + , Bu 4 N + , and Bu 3 MeN + ) picrates in water were determined by capillary electrophoresis at 25 • C. The ion-pair extraction constants (K ex,ip ) of the picrates from water to m-xylene were determined by a batch-extraction method at 25 • C, and the distribution constants (K D ) of the neutral ion-pairs were calculated from the relationship K D = K ex,ip /K IP . The tetraalkylammonium ion having more methylene groups generally forms a slightly more stable ion-pair with the picrate ion in water, which is attributed to the lower hydration of the cation. For Me 4 N + , Et 4 N + , Pr 4 N + , and Bu 4 N + , the distribution of the ion pair into m-xylene increases in that order, and a linear relationship was found between log K D and the number of methylene groups in the cation. This is consistently explained by the regular solution theory. It was also revealed that the ion pairs have a strong specific interaction with water. The ion pair of Bu 3 MeN + has a higher distribution constant than that expected from the relationship between log K D and the number of methylene groups for the symmetrical tetraalkylammonium ions. The cation dependence of the ion pair extractability is mostly governed by that of the distribution of the ion pair.

This IUPAC-NIST Solubility Data Series volume reviews experimentally determined solubility data for 33 nonsteroidal anti-inflammatory drugs (NSAIDs) dissolved in neat organic solvents and well-defined binary and ternary organic solvent mixtures retrieved from the published chemical and pharmaceutical literature covering the period from 1980 to the beginning of 2014. Except for aspirin (2-acetoxybenzoic acid) and salicylic acid (2-hydroxybenzoic acid), very little physical and chemical property data are available in the published literature for NSAIDs prior to 1980. Solubility data are compiled and critically reviewed for aclofenac, celecoxib, dexibuprofen, diclofenac,

In 1983, he became a Full Professor (Department of Chemistry) and he retired in 2007 (after chairing the Department for several years), but remained as Emeritus Professor for another decade, that is, from 2007 until 2018, when he finally withdrew from all activities in the Department. During his career, Jean-Pierre Grolier supervised 75 PhD dissertations and master's theses, and welcomed numerous visitors from abroad, i.e., students, post-docs, and scientists/collaborators. Honoring his five decades of dedication to thermodynamics, on

The solubility of propane (C3H8, component 2) in pure liquid water (H2O, component 1) was determined at a total pressure of about 100 kPa from about T = 278 K to T = 318 K using an analytical method characterized by an imprecision of about ± 0.1% or less. The measurements were made with a Benson-Krause-type apparatus at roughly 5 K intervals. From the experimental results, Henry’s law constants $$h_{2,1} \left( {T,P_{\sigma ,1} } \right)$$ h 2 , 1 T , P σ , 1 , also known as Henry fugacities, at the vapor pressure $$P_{\sigma ,1} \left( T \right)$$ P σ , 1 T of water, as well as the Ostwald coefficient $$L_{2,1}^{\infty } \left( {T,P_{{{\sigma ,}1}} } \right)$$ L 2 , 1 ∞ T , P σ , 1 at infinite dilution are rigorously obtained. The temperature dependence is accounted for by a three-constant Benson-Krause equation, i.e., by fitting $$\ln \left[ {{{h_{2,1} \left( {T,P_{\sigma ,1} } \right)} \mathord{\left/ {\vphantom {{h_{2,1} \left( {T,P_{\sigma ,1} } \right)}{\text {kPa}}}} \right. ...

The liquid state is one of the three principal states of matter and arguably the most important one; and liquid mixtures represent a large research field of profound theoretical and practical interest. This topic is of importance in many areas of the applied sciences, such as in chemical engineering, geochemistry, the environmental sciences, biophysics and biomedical technology. First, I will concisely present a review of important concepts from classical thermodynamics of nonelectrolyte solutions; this will be followed by a survey of (semi-)empirical approaches to representing the composition and temperature dependence of selected thermodynamic mixture properties, and finally the focus will be on dilute binary nonelectrolyte solutions where one component, a supercritical solute, is present in much smaller quantity than the other component, called the solvent. Partial molar properties in the limit of infinite dilution (indicated by a superscript ∞) are of particular interest. For in...

Bob Wood's interest in the physical chemistry of solutions now spans about five decades and is documented by his more than 150 published technical papers, the majority of which is devoted to the physical chemistry of aqueous solutions of electrolytes and nonelectrolytes. When the focus is on water as solvent, one has to realize that water is not only the most abundant substance on the surface of the earth, it is also the only substance on earth occurring naturally in all three states of matter. Water is important for the structure, the stability and the function of biomolecules, that is to say, it has a controlling influence on biochemical processes and is thus a prerequisite for the emergence of life as we know it. Professor Wood's scientific work may be subdivided roughly into six topics listed below. For each topic I have included one or more representative publications:

In 1983, he became a Full Professor (Department of Chemistry) and he retired in 2007 (after chairing the Department for several years), but remained as Emeritus Professor for another decade, that is, from 2007 until 2018, when he finally withdrew from all activities in the Department. During his career, Jean-Pierre Grolier supervised 75 PhD dissertations and master's theses, and welcomed numerous visitors from abroad, i.e., students, post-docs, and scientists/collaborators. Honoring his five decades of dedication to thermodynamics, on

We present a study of the structure and differential capacitance of electric double layers of aqueous electrolytes. We consider electric double layer capacitors (EDLC) composed of spherical cations and anions in a dielectric continuum confined between a planar cathode and anode. The model system includes steric as well as Coulombic ion-ion and ion-electrode interactions. We compare results of computationally expensive, but “exact” , Brownian Dynamics (BD) simulations with approximate, but cheap, calculations based on classical Density Functional Theory (DFT). Excellent overall agreement is found for a large set of system parameters, including variations in concentration, ionic size- and valency-asymmetries, applied voltages and electrode separation, provided the differences between the canonical ensemble of the BD simulations and the grand-canonical ensemble of DFT are properly taken into account. In particular, a careful distinction is made between the differential capacitance $$C_...

It is shown, by means of numerical and analytic work, that initial molecular momenta play little significant role in the initial fast solvation relaxation that follows electronic excitation of, and charge creation for, a standard model system of a solute in water. Instead, the nonequilibrium dynamics are predominantly described by non-inertial "steering" by the torques directly generated by the newly created charge distribution. It is this process that largely overcomes inertia, and drives the relaxation dynamics on a time scale of a few tens of femtoseconds in the key initial regime of the dynamics. These results are discussed in the context of commonly employed descriptions such as inertial, Gaussian, and underdamped dynamical behavior.

Fluorescence emission spectroscopy have been used to investigate the effects of electrolytes on the excited state intramolecular charge transfer (ICT) reaction in 4-(1azetidinyl)benzonitrile (P4C) in very dilute to concentrated electrolyte solutions of ethyl acetate (EA), acetonitrile (AN) and ethanol (EtOH). In the limit of very low electrolyte concentrations, the reaction rate (= 1/τ rxn , τ rxn being the reaction time) is found to decrease with increasing electrolyte concentration, the extent of decrease being the maximum in EA and the minimum in AN. At moderate to higher electrolyte concentrations, however, the rate increases upon further addition of electrolyte. The observed non-monotonic electrolyte concentration dependence of rate is believed to occur due to a novel interplay between friction and solvation experienced by the photo-excited reactant in solution. Moreover, the long time decay constant and amplitude of the bi-exponential decay of the time resolved fluorescence emission intensity also show a significant electrolyte concentration dependence which corroborates the relevant steady-state results.