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1.
In this communication, we demonstrate the solute–solvent and solvent–solvent interactions in the binary mixtures of two aprotic ionic liquids, namely 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, with the protic ionic liquid 1-methylimidazolium acetate. The synergistic effects as expressed by the solvatochromic parameter are noted. This observation is in contrast to the mixing of protic ionic liquids 1-methylpyrrolidium acetate and 4-methylmorpholine acetate with 1-methylimidazolium acetate, respectively. It appears that the synergistic effects in the binary mixtures of aprotic and protic ionic liquids are caused by the formation of hydrogen bonds, since cations are dominant H-bond donors while anions are dominant H-bond acceptors. Preferential solvation models are used to describe the solute–solvent interactions in the binary ionic liquid mixtures. 相似文献
2.
Farrokh Gharib Ali Shamel Fatemeh Jaberi Ali Farajtabar 《Journal of solution chemistry》2013,42(5):1083-1095
The solvatochromic properties of the free base and the protonated 5,10,15,20-tetrakis(4-trimethyl-ammonio-phenyl)-porphine tetratosylate (TTMAPP) were studied in pure water, methanol, ethanol, 2-propanol, and their corresponding aqueous mixtures. The correlation of the empirical solvent polarity scale (E T) values of TTMAPP with composition of the solvents were analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition effects in preferential solvation of the solute dyes were investigated in terms of both solvent–solvent and solute–solvent interactions and also the local mole fraction of each solvent composition was calculated in the cybotactic region of the probe. The effective mole fraction variation may provide significant physicochemical insights in the microscopic and molecular level of interactions between TTMAPP species and the solvent components and, therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TTMAPP. 相似文献
3.
《Monatshefte für Chemie / Chemical Monthly》2011,5(1):1227-1234
Abstract
A series of 5-substituted 5-phenylhydantoins was synthesized and their UV absorption spectra were recorded in the region 200–400 nm in selected solvents of different polarity. The effects of solvent dipolarity/polarizability and solvent–solute hydrogen-bonding interactions were analyzed by means of the linear solvation energy relationship concept proposed by Kamlet and Taft. The lipophilicities of the investigated hydantoins were estimated by calculation of their log P values. The quantitative relationship between the ratio of the contributions of specific solvent interactions and the corresponding lipophilicity parameter is discussed. The correlation equations were combined with the corresponding ED50 values and different physicochemical parameters to generate new equations that demonstrate the reasonable relationships between solute–solvent interactions and the structure–activity parameters. In order to determine a spectroscopic assignment of the absorption bands in different solvents, quantum chemical calculations were done. 相似文献4.
Farajtabar A Jaberi F Gharib F 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):213-220
The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale (E(T)) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO. 相似文献
5.
Fleming Martínez Abolghasem Jouyban William E. Acree Jr 《Physics and Chemistry of Liquids》2017,55(3):291-303
Preferential solvation parameters of etoricoxib in several aqueous cosolvent mixtures were calculated from solubilities and other thermodynamic properties by using the IKBI method. Cosolvents studied were as follows: 1,4-dioxane, N,N-dimethylacetamide, 1,4-butanediol, N,N-dimethylformamide, ethanol and dimethyl sulfoxide. Etoricoxib exhibits solvation effects, being the preferential solvation parameter δx1,3, negative in water-rich and cosolvent-rich mixtures but positive in mixtures with similar proportions of both solvents. It is conjecturable that the hydrophobic hydration in water-rich mixtures plays a relevant role in drug solvation. In mixtures of similar solvent proportions where etoricoxib is preferentially solvated by the cosolvents, the drug could be acting as Lewis acid with the more basic cosolvents. Finally, in cosolvent-rich mixtures the preferential solvation by water could be due to the more acidic behaviour of water. Nevertheless, the specific solute–solvent interactions in the different binary systems remain unclear because no relation between preferential solvation magnitude and cosolvent polarities has been observed. 相似文献
6.
Mohammad Khodadadi-Moghaddam Aziz Habibi-Yangjeh Mohamad Reza Gholami 《Monatshefte für Chemie / Chemical Monthly》2009,39(10):329-334
Abstract
Solvatochromic parameters (E T N, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (IL; 2-hydroxyethylammonium formate) at 25 °C. In all solutions except aqueous solution, E T N values of the media increase abruptly with the ILs mole fraction and then increase gradually to the value of pure IL. A synergistic behavior is observed for the α parameter in all solutions. The behavior of π* and β are nearly ideal for all solutions except for solutions of methanol with the IL. The applicability of nearly ideal combined binary solvent/Redlich–Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition. The correlation between the calculated and the experimental values of various parameters was in accordance with this model. Solute–solvent and solvent–solvent interactions were applied to interpret the results. 相似文献7.
A. Renee Siler Michael R. Brindza Robert A. Walker 《Analytical and bioanalytical chemistry》2009,395(4):1063-1073
Resonance-enhanced, second harmonic generation (SHG) is used to measure the electronic structure of solutes sensitive to specific
solvation adsorbed to liquid/liquid and liquid/solid interfaces. Here, specific solvation refers to solvent–solute interactions
that are directional and localized. N-methyl-p-methoxyaniline (NMMA) is a solute whose first allowed electronic transition wavelength remains almost constant (∼315 nm)
in non-hydrogen-bonding solvents regardless of solvent polarity. However, in hydrogen-bond-accepting solvents such as dimethylsulfoxide,
NMMA’s absorbance shifts to longer wavelengths (320 nm), whereas in hydrogen-bond-donating solvents (e.g., water), the absorbance
shifts to shorter wavelengths (∼300 nm). SHG experiments show that at alkane/silica interfaces, surface silanol groups serve
as moderately strong hydrogen-bond donors as evidenced by NMMA’s absorbance of 307 nm. At the carbon tetrachloride/water interface,
NMMA absorbance also shifts to slightly shorter wavelengths (298 nm) implying that water molecules at this liquid/liquid interface
are donating strong hydrogen bonds to the adsorbed NMMA solutes. In contrast, experiments using newly developed molecular
ruler surfactants with NMMA as a model hydrophobic solute and a hydrophilic, cationic headgroup imply that, as NMMA migrates
across an aqueous/alkane interface, it carries with it water that functions as a hydrogen-bond-accepting partner. 相似文献
8.
《Physics and Chemistry of Liquids》2012,50(4):533-545
The preferential solvation parameters of indomethacin and naproxen in ethyl acetate + ethanol mixtures are derived from their thermodynamic properties by using the inverse Kirkwood–Buff integrals method. It is found that both drugs are sensitive to solvation effects, so the preferential solvation parameter, δxEA,D, is negative in ethanol-rich and ethyl acetate-rich mixtures but positive in compositions from 0.36 to 0.71 in mole fraction of ethyl acetate. It is conjecturable that in ethanol-rich mixtures, the acidic interaction of ethanol on basic sites of the analgesics plays a relevant role in the solvation. The more solvation by ethyl acetate in mixtures of similar co-solvent compositions could be due to polarity effects. Finally, the slight preference of these compounds for ethanol in ethyl acetate-rich mixtures could be explained as the common participation of basic sites in both solvents and the acidic site of ethanol. Nevertheless, the specific solute–solvent interactions remain unclear. 相似文献
9.
Hadi Salari Seyedsaeid Ahmadvand Ali Reza Harifi-Mood Mohsen Padervand Mohammad Reza Gholami 《Journal of solution chemistry》2013,42(9):1757-1769
Structural and molecular-microscopic properties of the solvatochromic probes 4-nitroaniline, 4-nitroanisole, and Reichardt’s dye were investigated in binary mixtures of ethylammonium propionate with methanol, ethanol, 1-propanol and 2-propanol. Solvatochromic parameters (α, hydrogen-bond donor acidity; β, hydrogen-bond acceptor basicity; π*, dipolarity/polarizability; $ E_{\text{T}}^{\text{N}} $ , normalized polarity parameter) in different binary mixtures of ionic liquid with molecular solvents were determined with UV–Vis spectroscopy. The $ E_{\text{T}}^{\text{N}} $ parameters show nearly ideal trends in all solvent mixtures, but the other parameters show different behavior in the mixtures. The π* parameters show a negative deviation from ideality in the ionic liquid/methanol system. In contrast, the α parameters have severe positive deviations from ideal behavior in ionic liquid/1-propanol and ionic liquid/2-propanol solvent mixtures. A synergistic solvation effect is observed for the π* parameters in IL/methanol mixtures. Specific solute–solvent interactions or solvent–solvent interactions, which cause non-ideal trends in some parameters, are justified and interpreted by the preferential solvation model. 相似文献
10.
Enthalpies of Transfer of Tetraalkylammonium Bromides and CsBr from water to Aqueous DMF at 298.15 K
G. Rezaei Behbehani 《Journal of solution chemistry》2007,36(8):939-945
Enthalpies of transfer of tetraalkylammonium bromides and CsBr from water to aqueous DMF mixtures are reported and analyzed
in terms of a new solvation theory. It was found that a previous equation could not reproduce these data over the whole range
of solvent compositions. Using a new solvation theory to model the enthalpies of transfer shows excellent agreement between
experimental and calculated values over the entire range of solvent compositions. The analyses show that tetrapropylammonium
bromide, Pr4NBr, and tetrapentylammonium bromide, Pen4NBr, are preferentially solvated by water; in contrast tetrabutylammonium bromide, Bu4NBr, is preferentially solvated by DMF. The solvation of tetramethylammonium bromide, Me4NBr, and cesium bromide, CsBr, is random. The extent to which the tetraalkylammonium bromides disrupt solvent–solvent bonds
increases systematically in going from Me4NBr to Pen4NBr. 相似文献
11.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1993,49(7):903-912
The solvent effects on the electronic absorption spectra of 9,10-anthraquinone (AQ) and its symmetric dihydroxy derivatives namely 1,5-dihydroxyanthraquinone (1,5-DHAQ) and 2,6-dihydroxyanthraquinone (2,6-DHAQ) have been studied in pure solvents and some binary solvent mixtures. The frequencies of the absorption for AQ and 2,6-DHAQ are quite solvent sensitive while those for 1,5-DHAQ are not. Due to the intramolecular hydrogen bond between the CO and OH groups, no influence of solvent hydrogen bond acceptors is observed in 1,5-DHAQ. This hydrogen bond gives a stable six member cycle which is not broken even by the strongest hydrogen bond acceptor solvents used in this work, such as DMSO and DMF. The Taft and Kamlet's solvatochromic comparison method was applied for AQ and 2,6-DHAQ. Aromatic solvents and aliphatic amines were not included in the correlations since they strongly deviate suggesting another type of interactions. All the π→π* bands of AQ and 2,6-DHAQ show strong influence of π* despite the fact that their dipole moment is zero. Although it would be reasonable to expect that in the absence of a solute dipole moment there is not significant orientation of solvent molecules around the solute molecules, in this case dipolar interactions between solute and solvent due to local effects might be expected. AQ may be considered as formed by two carbonyl groups weakly interacting with the benzene rings; that means that the carbonyl group can behave as an isolated dipole and independently of the other. To detect possible specific interactions between the AQ and aliphatic amines and aromatic hydrocarbons, preferential solvation in mixed solvent was investigated. It is concluded that EDA interactions are important in the solvation of AQ with these compounds as solvents. 相似文献
12.
Mohammad Khodadadi-Moghaddam Aziz Habibi-Yangjeh Mohamad Reza Gholami 《Monatshefte für Chemie / Chemical Monthly》2009,140(3):329-334
Abstract Solvatochromic parameters (E
T
N, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and
water with recently synthesized ionic liquid (IL; 2-hydroxyethylammonium formate) at 25 °C. In all solutions except aqueous
solution, E
T
N values of the media increase abruptly with the ILs mole fraction and then increase gradually to the value of pure IL. A synergistic
behavior is observed for the α parameter in all solutions. The behavior of π* and β are nearly ideal for all solutions except for solutions of methanol with the IL. The applicability of nearly ideal combined
binary solvent/Redlich–Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition.
The correlation between the calculated and the experimental values of various parameters was in accordance with this model.
Solute–solvent and solvent–solvent interactions were applied to interpret the results.
Graphical Abstract Predicted values of solvatochromic parameters (SP) (E
T
N, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) from the correlation equations versus its experimental values for binary mixtures of 2-hydroxyethylammonium
formate with water, methanol, ethanol, propan-1-ol and propan-2-ol.
相似文献
13.
Viscosity B-coefficients for cesium chloride and lithium sulfate in methanol + water mixtures at 25 and 35 °C are reported. A general
treatment of the quasi-thermodynamics of viscous flow of electrolyte solutions is described. ΔG
3
Θ
(1→1′), the contribution made to the Gibbs energy of activation of the solution by the influence of the solute on the solvent,
is a function of solute–solvent interactions only; but, ΔH
3
Θ
(1→1′) and ΔS
3
Θ
(1→1′) also reflect the solvent–solvent interactions. In aqueous solution all alkali-metal ions except Li+ are sterically unsaturated, having solvent co-ordination numbers n<n
max , the maximum allowed sterically. Such complexes exchange molecules with the solvent more readily than saturated ones and
have energy–reaction co-ordinate diagrams in forms that explain the negative B or ΔG
3
Θ
(1→1′) values found in aqueous solution. Saturated complexes are the norm in non-aqueous solvents, and the ΔG
3
Θ
(1→1′) values are determined mainly by the secondary solvation. Behavior in mixed solvents reflects the transition from aqueous
to non-aqueous behavior across the range of solvent composition. 相似文献
14.
The reaction of 2‐bromo‐5‐nitrothiophene with morpholine was studied as an aromatic nucleophilic substitution reaction in various compositions of methanol with ethyl acetate and aqueous solution of methanol, ethanol, and propane‐2‐ol at 25°C. The second‐order rate coefficients of the reaction were spectrophotometerically determined. It was shown that a mounting trend with the mole fraction of water in aqueous solution of alcohols and a mild decreasing with the mole fraction of ethyl acetate in methanol–ethyl acetate mixtures. Solvent effect investigations based on linear free energy relationship (LFER) confirm that polarity has a major effect, whereas the hydrogen‐bond donor and acceptor abilities of the media have a minor effect on the reaction rate. A nonlinear free energy relationship based on preferential solvation hypothesis showed differences between the microsphere solvation of the solute and the bulk composition of the solvents, and nonideal behavior was observed in the trend of rate coefficients, which was consistent with LFER results. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 59–67, 2013 相似文献
15.
Previous studies have established that the extended coordination model of solvation can satisfactorily account for the variation in the transfer enthalpies of solutes in mixed-solvent systems. The model parameter relating to the solute-induced disruption of the solvent structure shows a marked dependence on the nature of the mixed solvent. In the present paper we report the transfer enthalpies of acetonitrile from water to aqueous methanol, ethanol and dimethylsulphoxide (DMSO) systems. Analysis of these in terms of the extended coordination model confirms both the model's ability to account for the experimental data, and the variability of the structural disruption parameter. The solvation parameters recovered from the analyses indicate that the net effect of acetonitrile on the solvent structure is a breaking of solvent-solvent bonds. The extent of bond breaking of the solvent increases from MeOH to EtOH. 相似文献
16.
Midori Yasuda Tamiyoshi Sonda Tomoko Hiraoka Aki Horita Masaaki Tabata 《Analytical sciences》2003,19(12):1637-1641
The retention behavior and mechanism of methyl, ethyl, propyl, isopropyl, buthyl and isobuthyl benzoates have been studied at different eluent compositions of aqueous mixtures with water-soluble organic solvents (methanol, ethanol, 1-propanol, 2-propanol, acetonitrile (AN), 1,4-dioxane and tetrahydrofuran (THF)) in RPLC. The retention of the solutes is discussed based on the solvent composition, solvent polarity (ETN value), preferential solvation, hydrogen bonding and solvent clusters of the eluents. The smaller ETN values and the larger preferential solvation of the mixed solvent eluted the solutes faster. The IR spectra of HDO suggested that the solvents, except for methanol and ethanol, break the hydrogen bonding between water molecules, resulting in fast elution of the solutes. Based upon the results, we chose an optimum solvent composition for the separation of benzoates and applied it to the determination of the benzoates in clove. 相似文献
17.
密度法测定了298.15 K下乙醇、环己烷、三氯甲烷、甲苯、丙酮、四氯化碳、乙腈、二甲基甲酰胺、二甲基亚砜在甲醇或苯及两者混合物中的无限稀释偏摩尔体积. 密度测定所用溶液中溶质的浓度范围是0.2一1.5 m; 甲醇和苯混合物是全组成比范围. 溶质偏摩尔体积随甲醇-苯组成比的变化趋势反映了几种分子间相互作用结果即三种分子间物理型分子间相互作用; 溶质与甲醇分子氢键缔合相互作用; 溶质同甲醇或苯的弱络合作用。 相似文献
18.
We have carried out a series of molecular dynamics simulations of water containing a narrow carbon nanotube as a solute to
investigate the filling and emptying of the nanotube and also the modifications of the density and hydrogen bond distributions
of water inside and also in the vicinity of the outer surfaces of the nanotube. Our primary goal is to look at the effects
of varying nanotube diameter, wall thickness and also solute-solvent interactions on the solvent structure in the confined
region also near the outer surfaces of the solute. The thickness of the walls is varied by considering single and multi-walled
nanotubes and the interaction potential is varied by tuning the attractive strength of the 12–6 pair interaction potential
between a carbon atom of the nanotubes and a water molecule. The calculations are done for many different values of the tuning
parameter ranging from fully Lennard-Jones to pure repulsive pair interactions. It is found that both the solvation characteristics
and hydrogen bond distributions can depend rather strongly on the strength of the attractive part of the solute-water interaction
potential. The thickness of the nanotube wall, however, is found to have only minor effects on the density profiles, hydrogen
bond network and the wetting characteristics. This indicates that the long range electrostatic interactions between water
molecules inside and on the outer side of the nanotube do not make any significant contribution to the overall solvation structure
of these hydrophobic solutes. The solvation characteristics are primarily determined by the balance between the loss of energy
due to hydrogen bond network disruption, cavity repulsion potential and offset of the same by attractive component of the
solute-water interactions. Our studies with different system sizes show that the essential features of wetting and dewetting
characteristics of narrow nanotubes for different diameter and interaction potentials are also present in relatively smaller
systems consisting of about five hundred molecules.
We dedicate this work to Professor Debashis Mukherjee on his 60th Birthday. 相似文献
19.
Solvation characteristics of a ketocyanine dye have been studied in completely miscible ternary solvent mixtures, namely, methanol + acetone + water and methanol + acetone + benzene, by monitoring the solvatochromic absorption band of the dye. The maximum energy of absorption (E) of the solute in a ternary solvent mixture differs significantly from the mole fraction average of the E values in the component solvents. Results in the corresponding binary solvent mixtures also show a deviation of the E value from the mole fraction averaged E values. The results have been explained in terms of preferential solvation using a two phase model of solvation. The excess or deficit over the bulk composition of a solvent component in the vicinity of the solute molecule in a ternary solvent mixture has been estimated using the knowledge of solvation in the corresponding binary mixtures. 相似文献
20.
Bevilaqua T da Silva DC Machado VG 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(4):951-958
The ET polarity values of 4-[(1-methyl-4(1H)-pyridinylidene)-ethylidene]-2,5-cyclohexadien-1-one (Brooker's merocyanine) were collected in mixed-solvent systems comprising a formamide [N,N-dimethylformamide (DMF), N-methylformamide (NMF) or formamide (FA)] and a hydroxylic (water, methanol, ethanol, propan-2-ol or butan-1-ol) solvent. Binary mixtures involving DMF and the other formamides (NMF and FA) as well as NMF and FA were also studied. These data were employed in the investigation of the preferential solvation (PS) of the probe. Each solvent system was analyzed in terms of both solute-solvent and solvent-solvent interactions. These latter interactions were responsible for the synergism observed in many binary mixtures. This synergistic behaviour was observed for DMF-propan-2-ol, DMF-butan-1-ol, FA-methanol, FA-ethanol and for the mixtures of the alcohols with NMF. All data were successfully fitted to a model based on solvent-exchange equilibria, which allowed the separation of the different contributions of the solvent species in the solvation shell of the dye. The results suggest that both hydrogen bonding and solvophobic interactions contribute to the formation of the solvent complexes responsible for the observed synergistic effects in the PS of the dye. 相似文献