From Hydrophobic to Hydrophilic Solvation:  An Application to Hydration of Benzene

Schravendijk, Pim; Vegt, Nico F. A. van der

doi:10.1021/ct049841c

Cited by 63 publications

(80 citation statements)

References 37 publications

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“…This is readily understandable if the clustering of water around large hydrophobic residues is considered. For instance, the large value of ln γ for the napsylate salt may be due in some part to the more unfavorable entropic contribution exhibited by aromatic compounds (33,34).…”

Section: Aqueous Solubilitymentioning

confidence: 99%

Analysis of Relationships Between Solid-State Properties, Counterion, and Developability of Pharmaceutical Salts

Guerrieri

Rumondor

et al. 2010

AAPS PharmSciTech

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Abstract. The solid-state properties of pharmaceutical salts, which are dependent on the counterion used to form the salt, are critical for successful development of a stable dosage form. In order to better understand the relationship between counterion and salt properties, 11 salts of procaine, which is a base, were synthesized and characterized using a variety of experimental and computational methods. Correlations between the various experimental and calculated physicochemical properties of the salts and counterions were probed. In addition to investigating the key factors affecting solubility, the hygroscopicity of the crystalline salts was studied to determine which solid-state and counterion properties might be responsible for enhancements in moisture uptake, thus providing the potential for adverse chemical stability. Multivariate principal components and partial least squares projection to latent structures analyses were performed in an attempt to establish predictive models capable of describing the relationships between these characteristics and both measured and calculated properties of the counterion and salt. Some success was achieved with respect to modeling crystalline salt solubility and the glass transition temperature of the amorphous salts. Through the modeling, insight into the relative importance of various descriptors on salt properties was achieved. The solid-state properties of crystalline and amorphous salts of procaine are highly dependent on the nature of the counterion. Important properties including aqueous solubility, melting point, hygroscopicity, and glass transition temperature were found to vary considerably between the different salts.

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Section: Aqueous Solubilitymentioning

confidence: 99%

Analysis of Relationships Between Solid-State Properties, Counterion, and Developability of Pharmaceutical Salts

Guerrieri

Rumondor

et al. 2010

AAPS PharmSciTech

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“…[25] The all-atom benzene model includes a permanent charge distribution, which can be expressed by an electrostatic multipole expansion where the quadrupole moment is the first nonzero term. The thermodynamic properties of this system (i.e., the benzene hydration enthalpy and entropy at infinite dilution) were calculated and showed differences of % 5 % (entropy) and % 1 % (enthalpy) compared to the experimentally reported values at 298 K. [26] Molecular dynamics simulations were performed using the Gromacs 3.2.1 MD simulation package. [27,28] All simulations were performed at constant volume and temperature (T = 298 K) using a Berendsen weak-coupling thermostat, [29] with relaxation time t = 0.1 ps.…”

Section: Molecular Dynamics Implementationmentioning

confidence: 99%

Dual‐Scale Modeling of Benzene Adsorption onto Ni(111) and Au(111) Surfaces in Explicit Water

et al. 2005

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We present a multiscale modeling approach for studying interactions of organic molecules with metal surfaces in explicit water. The approach is based on combining adsorption energies of isolated molecules on transition metal surfaces calculated by ab initio density functional methods and classical molecular dynamics simulations using atomistically detailed force fields. The interaction of benzene with Ni(111) and Au(111) surfaces was studied. It is shown that a strong affinity of water for the hydrophilic surfaces makes benzene adsorption on Au thermodynamically unfavorable, while on Ni there is no preference. The work presented here serves as a first step in modeling the interactions of larger organic molecules with metal surfaces.

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“…This exact enthalpyentropy compensating contribution has been described in several earlier works, 1,4-13 but its quantitative evaluation in numerical simulations remains challenging, and only a few numerical studies have been reported on this subject so far. 1,4,7,[9][10][11] This paper is organized as follows. In section 2, we start with describing the statistical mechanics basis of the solvation entropy.…”

Section: Introductionmentioning

confidence: 99%

Confusing Cause and Effect: Energy−Entropy Compensation in the Preferential Solvation of a Nonpolar Solute in Dimethyl Sulfoxide/Water Mixtures

Özal

Vegt

2006

J. Phys. Chem. B

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We performed molecular simulations to analyze the thermodynamics of methane solvation in dimethyl sulfoxide (DMSO)/water mixtures (298 K, 1 atm). Two contributions to the interaction thermodynamics are studied separately: (i) the introduction of solute-solvent interactions (primary contribution) and (ii) the solute-induced disruption of cohesive solvent-solvent interactions (secondary contribution). The energy and entropy changes of the secondary contribution always exactly cancel in the free energy (energy-entropy compensation), hence only the primary contribution is important for understanding changes of the free energy. We analyze the physical significance of the solute-solvent energy and solute-solvent entropy associated with the primary contribution and discuss how to obtain these quantities from experiments combining solvation thermodynamic and solvent equation of state data. We show that the secondary contribution dominates changes in the methane solvation entropy and enthalpy: below 30 mol % DMSO in the mixture, methane, because of more favorable dispersion interactions with DMSO molecules, preferentially attracts DMSO molecules, which, in response, release water molecules into the bulk, causing an increase in the entropy. This large energy-entropy compensating process easily causes a confusion in the cause for and the effect of preferred methane-DMSO interactions. Methane-DMSO dispersion interactions are the cause, and the entropy change is the effect. Procedures that infer thermodynamic driving forces from analyses of the solvation entropies and enthalpies should therefore be used with caution.

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From Hydrophobic to Hydrophilic Solvation: An Application to Hydration of Benzene

Cited by 63 publications

References 37 publications

Analysis of Relationships Between Solid-State Properties, Counterion, and Developability of Pharmaceutical Salts

Analysis of Relationships Between Solid-State Properties, Counterion, and Developability of Pharmaceutical Salts

Dual‐Scale Modeling of Benzene Adsorption onto Ni(111) and Au(111) Surfaces in Explicit Water

Confusing Cause and Effect: Energy−Entropy Compensation in the Preferential Solvation of a Nonpolar Solute in Dimethyl Sulfoxide/Water Mixtures

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