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    QSPR studies for predicting gas to acetone and gas to acetonitrile solvation enthalpies using support vector machine

    , Article Journal of Molecular Liquids ; Volume 175 , 2012 , Pages 24-32 ; 01677322 (ISSN) Toubaei, A ; Golmohammadi, H ; Dashtbozorgi, Z ; Acree Jr., W. E ; Sharif Unviersity of Technology
    2012
    Abstract
    Quantitative structure-properties relationship (QSPR) has been applied to modelling and predicting the gas to acetone and gas to acetonitrile solvation enthalpies (ΔH Solv) of organic compounds using partial least squares (PLS), artificial neural network (ANN) and support vector machine (SVM) techniques. Two different datasets were assessed. The first one contained a set of gas to acetone enthalpy of solvation data of 68 different organic compounds while the second one included a total of 69 experimental data points for the enthalpy of solvation in acetonitrile. Genetic algorithm (GA) was used to search the descriptor space and select the descriptors responsible for property. After the... 

    Theoretical investigation of the enhanced solubility of perfluorobenzene in the supercritical carbon dioxide as a function of temperature and density by Monte Carlo simulation

    , Article Chemical Physics Letters ; Volume 444, Issue 1-3 , 2007 , Pages 48-55 ; 00092614 (ISSN) Tafazzoli, M ; Khanlarkhani, A ; Sharif University of Technology
    2007
    Abstract
    The absolute free energy of solvation of benzene and perfluorobenzene was measured in supercritical carbon dioxide using the expanded-ensemble method in the context of Monte Carlo (MC) Simulations. The MC calculations were carried out at 12 state points on the solvent phase diagram: (ρr = 0.5, 1.0, 1.5, 2.0; Tr = 1.01, 1.10, and 1.20). These conditions were chosen to address the accurance of specific molecular interactions between CO2 and fluorine. The greater stability of perfluorobenzene observed over all states investigated in this study attributed to the greater solvent accessible surface area and 25-30% increase in the strength of the interaction of this molecule with CO2 in the... 

    Molecular-microscopic properties and preferential solvation in protic ionic liquid mixtures

    , Article Journal of Solution Chemistry ; Volume 42, Issue 9 , October , 2013 , pp. 1757-1769 ; 1572-8927 Salari, H. (Hadi) ; Ahmadvand, S. (Seyedsaeid) ; Harifi-Mood, A. R. (Ali Reza) ; Padervand, M. (Mohsen) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    Abstract
    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; ENT , normalized polarity parameter) in different binary mixtures of ionic liquid with molecular solvents were determined with UV–Vis spectroscopy. The ENT 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... 

    Reaction kinetics investigation of 1-fluoro-2,4-dinitrobenzene with substituted anilines in ethyl acetate–methanol mixtures using linear and nonlinear free energy relationships

    , Article Journal of Physical Organic Chemistry ; Volume 24, Issue 11 , November , 2011 , pages 1095–1100 Jamali-Paghaleh, J. (Javad) ; Harifi-Mood, A. R. (Ali Reza) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    Abstract
    Aromatic nucleophilic substitution reaction of 1-fluoro-2,4-dinitrobenzene with para-substituted and meta-substituted anilines was kinetically investigated in the mixtures of ethyl acetate and methanol at room temperature. The correlation of second-order rate coefficients with Hammett's substituent constants yields a fairly linear straight line with negative slope in different mole fractions of ethyl acetate–methanol mixtures. The measured rate coefficients of the reaction demonstrated a dramatic variation in ethyl acetate–methanol mixtures with the increasing mole fraction of ethyl acetate. Linear free energy relationship (LFER) investigations confirm that polarity has a major effect on the... 

    Molecular-microscopic properties and preferential solvation in protic ionic liquid mixtures

    , Article Journal of Solution Chemistry ; Volume 42, Issue 9 , 2013 , Pages 1757-1769 ; 00959782 (ISSN) Salari, H ; Ahmadvand, S ; Harifi-Mood, A. R ; Padervand, M ; Gholami, M. R ; Sharif University of Technology
    2013
    Abstract
    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; ET N, normalized polarity parameter) in different binary mixtures of ionic liquid with molecular solvents were determined with UV-Vis spectroscopy. The ET N parameters show nearly ideal trends in all solvent mixtures, but the other parameters show different behavior in the mixtures. The πparameters show a negative deviation... 

    Reaction kinetics investigation of 1-fluoro-2,4-dinitrobenzene with substituted anilines in ethyl acetate-methanol mixtures using linear and nonlinear free energy relationships

    , Article Journal of Physical Organic Chemistry ; Volume 24, Issue 11 , 2011 , Pages 1095-1100 ; 08943230 (ISSN) Jamali Paghaleh, J ; Harifi Mood, A. R ; Gholami, M. R ; Sharif University of Technology
    Abstract
    Aromatic nucleophilic substitution reaction of 1-fluoro-2,4-dinitrobenzene with para-substituted and meta-substituted anilines was kinetically investigated in the mixtures of ethyl acetate and methanol at room temperature. The correlation of second-order rate coefficients with Hammett's substituent constants yields a fairly linear straight line with negative slope in different mole fractions of ethyl acetate-methanol mixtures. The measured rate coefficients of the reaction demonstrated a dramatic variation in ethyl acetate-methanol mixtures with the increasing mole fraction of ethyl acetate. Linear free energy relationship (LFER) investigations confirm that polarity has a major effect on the... 

    Surfactant binary systems: Ab initio calculations, preferential solvation, and investigation of solvatochromic parameters

    , Article Journal of Chemical and Engineering Data ; Volume 61, Issue 1 , 2016 , Pages 255-263 ; 00219568 (ISSN) Kohantorabi, M ; Salari, H ; Fakhraee, M ; Gholami, M.R ; Sharif University of Technology
    American Chemical Society 
    Abstract
    Solvatochromic UV-vis shifts of three probes 4-nitroaniline, 4-nitroanisol, and Reichardt's dye in binary mixtures of polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether (Triton X-100 or TX-100) with methanol, ethanol, 1-propanol, and water have been investigated at 298 K. Structural and intermolecular interactions of solvatochromic probes were determined in these systems. Solvatochromic parameters, including normalized polarity (ETN), dipolarity-polarizability (π∗), hydrogen-bond donor (α), and hydrogen-bond acceptor (β) abilities, were measured at a wide range of mole fraction (0 ≤ X ≤ 1) with 0.1 increment. Interestingly, a similar behavior of ETN and α is observed in... 

    Solvation thermodynamics of hydroxyl and carbonyl group in supercritical CO2 by Monte Carlo simulations

    , Article Chemical Physics Letters ; Volume 458, Issue 4-6 , 2008 , Pages 308-312 ; 00092614 (ISSN) Tafazzoli, M ; Khanlarkhani, A ; Sharif University of Technology
    2008
    Abstract
    The Helmholtz free energy of solvation (ΔslvA) of 2-propanol and acetone in supercritical CO2 were calculated by expanded-ensemble method. For both solute molecules, ΔslvA is well represented by the polynomial equation of the third power of density and the density value correspond to the maximum stability decreases with increasing temperature. In all states under study acetone is more stable than 2-propanol. At low densities the solvation of acetone is more exothermic than 2-propanol while at high densities it come with less entropic penalty. The solvent reorganization energy is more favorable in 2-propanol case, although the role of solute-solvent interactions is dominant in both cases. ©... 

    Solvation free energy and solubility of acetaminophen and ibuprofen in supercritical carbon dioxide: Impact of the solvent model

    , Article Journal of Supercritical Fluids ; Volume 109 , 2016 , Pages 166-176 ; 08968446 (ISSN) Noroozi, J ; Ghotbi, C ; Jahanbin Sardroodi, J ; Karimi Sabet, J ; Robert, M. A ; Sharif University of Technology
    Elsevier  2016
    Abstract
    Classical molecular dynamics simulations are used to compute the solvation free energy of two pharmaceutical solids, namely ibuprofen and acetaminophen in carbon dioxide (CO2), over the density range of interest in supercritical processes. In order to examine the influence of the solvent model on the resulting free energies, three popular CO2 models (Zhang, EPM2, and TraPPE) are studied. Relatively large discrepancies for the solvation free energy exist between these CO2 models, suggesting that the former is sensitive to the different balances between dispersive and electrostatic forces used in these models. In particular, for the solvation of the highly polar (dipole moment of ∼5.2 Debye)... 

    Solubility of H2S in ionic liquids [hmim][PF6], [hmim][BF4], and [hmim][Tf2N]

    , Article Journal of Chemical Thermodynamics ; Volume 41, Issue 9 , 2009 , Pages 1052-1055 ; 00219614 (ISSN) Rahmati Rostami, M ; Ghotbi, C ; Hosseini Jenab, M ; Ahmadi, A. N ; Jalili, A. H ; Sharif University of Technology
    2009
    Abstract
    The solubility of hydrogen sulphide in three ionic liquids, viz. 1-hexyl-3-methylilmidazolium hexafluorophosphate ([hmim][PF6]), 1-hexyl-3-methylimidazolium tetrafluoroborate ([hmim][BF4]), and 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([hmim][Tf2N]), at temperatures ranging from 303.15 K to 343.15 K and pressures up to 1.1 MPa were determined. The solubility values were correlated using the Krichevsky-Kasarnovsky equation and Henry's constants were obtained at different temperatures. Partial molar thermodynamic functions of solvation such as standard Gibbs free energy, enthalpy, and entropy were calculated from the solubility results. Comparison of the values obtained... 

    Investigation of the enhanced solubility of fluorinated methanes in CO2 by Monte Carlo simulation: Absolute free energy of solvation and structural properties of solution

    , Article Journal of Supercritical Fluids ; Volume 40, Issue 1 , 2007 , Pages 40-49 ; 08968446 (ISSN) Tafazzoli, M ; Khanlarkhani, A ; Sharif University of Technology
    Elsevier  2007
    Abstract
    The absolute free energy of solvation of methane (CH4) and its fluorinated forms (CH3F, CH2F2, CHF3 and CF4) have been computed via statistical perturbation theory (SPT) in the NPT ensemble at four thermodynamical states (whitin liquid and supercritical regions), in the context of Monte Carlo Simulations. Thermodynamical interpretation of the observed trend in the absolute free energy of solvation in different states reveals an exothermic solvation with ΔSslv < 0 (entropically unfavorable solvation) that the intermolecular interactions play an important role in the solvation process. The fluorinated methanes are confirmed to control the mutual arrangement of neighboring CO2 molecules and the... 

    Preferential solvation and behavior of solvatochromic indicators in mixtures of an ionic liquid with some molecular solvents

    , Article The Journal of Physical Chemistry B ; vol.114 (29) , July , 2010 , pp 9586–9593 Salari, H. (Hadi) ; Khodadadi-Moghaddam, M.(Mohammad) ; Harifi-Mood, A. R. (Ali Reza) ; Gholami, M. R. (Mohammad Reza) ; Sharif University of Technology
    Abstract
    Structural and intermolecular interactions of solvatochromic probes 4-nitroaniline, 4-nitroanisole, and Reichardt’s dye were investigated in the binary mixtures of 2-hydroxy ethylammonium formate as an ionic liquid with N,N-dimethyl formamide, dimethyl amine, and dimethyl sulfoxide. Solvatochromic parameters (ETN, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen -bond donor acidity) were determined in ionic liquid mixtures at 25 °C using UV−vis spectroscopy. ETN parameters obtained from absorbance of Reichardt’s dye within various mixtures of ionic liquid were observed to be higher than predicted values from ideal additive... 

    Preferential solvation and behavior of solvatochromic indicators in mixtures of an ionic liquid with some molecular solvents

    , Article Journal of Physical Chemistry B ; Volume 114, Issue 29 , 2010 , Pages 9586-9593 ; 15206106 (ISSN) Salari, H ; Khodadadi Moghaddam, M ; Harifi Mood, A. R ; Gholami, M. R ; Sharif University of Technology
    American Chemical Society  2010
    Abstract
    Structural and intermolecular interactions of solvatochromic probes 4-nitroaniline, 4-nitroanisole, and Reichardts dye were investigated in the binary mixtures of 2-hydroxy ethylammonium formate as an ionic liquid with N,N-dimethyl formamide, dimethyl amine, and dimethyl sulfoxide. Solvatochromic parameters (ETN, normalized polarity parameter; π, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen -bond donor acidity) were determined in ionic liquid mixtures at 25°C using UV-vis spectroscopy. ETN parameters obtained from absorbance of Reichardt dye within various mixtures of ionic liquid were observed to be higher than predicted values from ideal additive behavior.... 

    Probing solvent-solvent and solute-solvent interactions in surfactant binary mixtures: Solvatochromic parameters, preferential solvation, and quantum theory of atoms in molecules analysis

    , Article RSC Advances ; Volume 6, Issue 22 , 2016 , Pages 18515-18524 ; 20462069 (ISSN) Kohantorabi, M ; Fakhraee, M ; Salari, H ; Gholami, M. R ; Sharif University of Technology
    Royal Society of Chemistry 
    Abstract
    The behaviour of solvatochromic absorbance probes (4-nitroaniline, 4-nitroanisole, and Reichardt's dye) within binary mixtures of polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether (Triton X-100 or TX-100)/organic solvents (2-propanol, hexanol, butyl acetate, THF, toluene, and p-xylene) was extensively explored by using solvatochromism and the quantum theory of atoms in molecules (QTAIM). To be more precise, the polarity parameters, ET N, and Kamlet-Taft parameters, such as the hydrogen bond donor ability (HBD) (α), hydrogen bond acceptor ability (HBA) (β), and dipolarity/polarizability (π∗), have been investigated in selected mixtures at 298 K. All binary mixtures exhibit complex... 

    Study of Solvent-Solvent and Solute-Solvent Interactions and Measurement of Solvatochromic Parameters in Mixture of Molecular Solvents with Solvents

    , M.Sc. Thesis Sharif University of Technology Kohantorabi, Mona (Author) ; Gholami, Mohammad (Supervisor) ; Rahman Setayesh, Shahrbano (Supervisor) ; Salari, Hadi (Co-Advisor)
    Abstract
    Solvent-solvent and solute-solvent interactions were investigated in mixtures of Triton X-100 with water, methanol, ethanol, 1-propanol, tetrahydrofuran and butyl acetate. Solvatochromic parameters, including normalized polarity (E_T^N), dipolarity-polarizability (), hydrogen-bond donar (), and hydrogen-bond acceptor () abilities, were determined in these mixtures. We observed similar behavior for E_T^N and  in TX-100/alcohols mixtures. Parameters confirmed the preferential solvation in mixtures of surfactant and solvents.
    Experimental data were handled in preferential solvation model. Six binary systems exhibit a complex behavior for all three indicators. It was shown that... 

    Microscopic structure and solubility predictions of multifunctional solids in supercritical carbon dioxide: a molecular simulation study

    , Article Journal of Physical Chemistry B ; Volume 121, Issue 7 , 2017 , Pages 1660-1674 ; 15206106 (ISSN) Noroozi, J ; Paluch, A. S ; Sharif University of Technology
    Abstract
    Molecular dynamics simulations were employed to both estimate the solubility of nonelectrolyte solids, such as acetanilide, acetaminophen, phenacetin, methylparaben, and lidocaine, in supercritical carbon dioxide and understand the underlying molecular-level driving forces. The solubility calculations involve the estimation of the solute's limiting activity coefficient, which may be computed using conventional staged free-energy calculations. For the case of lidocaine, wherein the infinite dilution approximation is not appropriate, we demonstrate how the activity coefficient at finite concentrations may be estimated without additional effort using the dilute solution approximation and how... 

    Extraction of molybdenum (VI) and vanadium (V) from nitrate solutions using coupling of acid and solvating extractants

    , Article International Journal of Engineering, Transactions A: Basics ; Volume 32, Issue 10 , 2019 , Pages 1366-1371 ; 17281431 (ISSN) Shakib, B ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
    Materials and Energy Research Center  2019
    Abstract
    In this study, solvent extraction method has been utilized for separation of molybdenum and vanadium from nitrate solution by utilizing coupling of acid and solvating extractants (D2EHPA and TBP extractants). The outcomes demonstrated that synergistic solvent extraction improves stability of formatted complexes for transfer to the organic phase. The main parameters such as pH value, concentration of extractants, NH4OH concentration as the stripping agent and contact time were optimized at 0.4, 15% (v/v) D2EHPA, 10% (v/v) TBP, 2 M and 30 min, respectively. The maximum separation factor of 24.84 was obtained with a new synergistic mixture of D2EHPA and TBP diluted with kerosene. According to... 

    Extraordinary swelling behavior of poly (AMPS) organogelin solvent/DMSO binary mixed media

    , Article Journal of Applied Polymer Science ; Volume 117, Issue 2 , July , 2010 , Pages 1127-1136 ; 00218995 (ISSN) Zohuriaan Mehr, M. J ; Kabiri, K ; Kheirabadi, M ; Sharif University of Technology
    2010
    Abstract
    The present article deals with super-swelling behavior of crosslinked homopolymer of 2-acrylamido-2-methylpropane sulfonic acid, poly(AMPS), in binary mixtures of dimethyl sulfoxide (DMSO) and various polar solvents including water, mono-, and polyhydric alcohols, and amide solvents such as N-methyl pyrrolidone. Extraordinary phase transition sequences including a new unusual swelling phenomenon, referred to as "overentrant" swelling, was observed for this polymeric organogel in the solvent/DMSO mixtures. The swelling behaviors were preliminarily explained based on the major interactions involved in the solvation process and dielectric constant of the swelling media. It was established that... 

    Systems designed with an ionic liquid and molecular solvents to investigate the kinetics of an SNAr reaction

    , Article Progress in Reaction Kinetics and Mechanism ; Volume 38, Issue 2 , 2013 , Pages 157-170 ; 14686783 (ISSN) Salari, H ; Hallett, J. P ; Padervand, M ; Gholami, M. R ; Sharif University of Technology
    2013
    Abstract
    The microscopic features of binary solvent systems formed by molecular solvents (methanol, ethanol, 2-methylpropan-2-ol, water, pyridine, acetonitrile, 1-propanol, 2-propanol, dimethylformamide) and the ionic liquid ([bmim]BF 4) as cosolvent were used to select mixed solvents with particular characteristics. Molecular-microscopic solvent parameters corresponding to these binary mixtures were utilised to study the kinetics of the nucleophilic substitution reaction between 2-chloro-3,5-dinitropyridine and aniline to investigate and compare the effects of the solvents on a model chemical reaction. For these mixtures, the solvation behaviour is dominated by both the dipolarity/ polarisability... 

    Effect of hydrogen bonds on pK a values: Importance of networking

    , Article Journal of the American Chemical Society ; Volume 134, Issue 25 , 2012 , Pages 10646-10650 ; 00027863 (ISSN) Shokri, A ; Abedin, A ; Fattahi, A ; Kass, S. R ; Sharif University of Technology
    2012
    Abstract
    The pK a of an acyclic aliphatic heptaol ((HOCH 2CH 2CH(OH)CH 2) 3COH) was measured in DMSO, and its gas-phase acidity is reported as well. This tertiary alcohol was found to be 10 21 times more acidic than tert-butyl alcohol in DMSO and an order of magnitude more acidic than acetic acid (i.e., pK a = 11.4 vs 12.3). This can be attributed to a 21.9 kcal mol -1 stabilization of the charged oxygen center in the conjugate base by three hydrogen bonds and another 6.3 kcal mol -1 stabilization resulting from an additional three hydrogen bonds between the uncharged primary and secondary hydroxyl groups. Charge delocalization by both the first and second solvation shells may be used to facilitate...