Vapor pressures and standard molar enthalpies, entropies, and Gibbs free energies of sublimation of 2,4- and 3,4-dinitrobenzoic acids

Vecchio, Stefano; Brunetti, Bruno

doi:10.1016/j.jct.2009.02.008

Cited by 21 publications

(19 citation statements)

References 21 publications

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“…Furthermore, from the mass loss rates of acetanilide determined in the temperature interval between 427.2 and 458.2 K using Eq. (2), the logarithmic form of two instrumental constants (a sort of empirical vaporization constants) related the two TG operative methods, ln(k cal ), have been reported as a function of temperature in Table 1 lent agreement with the corresponding average value reported in a previous paper (ln(k cal /kg 0.5 s −1 m (K mol) −0.5 ) = 12.54) in which benzoic acid was also considered as recommended reference compound [27].…”

Section: Influence Of Diffusion On Mass Loss Rate and Calibration Of supporting

confidence: 86%

Vapor pressures and standard molar enthalpies, entropies and Gibbs energies of sublimation of three 4-substituted acetanilide derivatives

Vecchio

Tomassetti

2009

Fluid Phase Equilibria

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Section: Influence Of Diffusion On Mass Loss Rate and Calibration Of supporting

confidence: 86%

Vapor pressures and standard molar enthalpies, entropies and Gibbs energies of sublimation of three 4-substituted acetanilide derivatives

Vecchio

Tomassetti

2009

Fluid Phase Equilibria

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“…X-ray structures were not always available or suitable for all molecules in SUB-158; − the theoretical chemistry terms are therefore inaccessible for some of the molecules. The predictions of the sublimation thermodynamics of SUB-158 are therefore carried out with only CDK descriptors.…”

Section: Methodsmentioning

confidence: 99%

Are the Sublimation Thermodynamics of Organic Molecules Predictable?

McDonagh

Palmer

Mourik

et al. 2016

J. Chem. Inf. Model.

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We compare a range of computational methods for the prediction of sublimation thermodynamics (enthalpy, entropy and free energy of sublimation). These include a model from theoretical chemistry that utilizes crystal lattice energy minimization (with the DMACRYS program) and QSPR models generated by both machine learning (Random Forest and Support Vector Machines) and regression (Partial Least Squares) methods. Using these methods we investigate the predictability of the enthalpy, entropy and free energy of sublimation, with consideration of whether such a method may be able to improve solubility prediction schemes. Previous work has suggested that the major source of error in solubility prediction schemes involving a thermodynamic cycle via the solid state is in the modeling of the free energy change away from the solid state. Yet contrary to this conclusion other work has found that the inclusion of terms such as the enthalpy of sublimation in QSPR methods 2 does not improve the predictions of solubility. We suggest the use of theoretical chemistry terms, detailed explicitly in the methods section, as descriptors for the prediction of the enthalpy and free energy of sublimation. A dataset of 158 molecules with experimental sublimation thermodynamics values and some CSD refcodes has been collected from the literature and is provided with their original source references.

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“…Note that eqn (1) assumes that the vaporization coefficient is unity. 4 Standard substances with well-known vapor pressures were used for calibration of the cells: benzoic acid 16,[17][18][19][20] and cadmium. 21 The following values of the constant have been determined for the cells A, B and C, respectively: K A = (3953 AE 82) Â 10 3 Pa s (g mol K) À1/2 , K B = (4500 AE 75) Â 10 2 Pa s (g mol K) À1/2 and K C = (710 AE 25) Â 10 2 Pa s (g mol K) À1/2 .…”

Section: Knudsen Effusion Mass Loss (Keml)mentioning

confidence: 99%

Vaporization of the prototypical ionic liquid BMImNTf2 under equilibrium conditions: a multitechnique study

Brunetti

Ciccioli

Gigli

et al. 2014

Phys. Chem. Chem. Phys.

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The vaporization behaviour and thermodynamics of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide (BMImNTf2) were studied by combining the Knudsen Effusion Mass Loss (KEML) and Knudsen Effusion Mass Spectrometry (KEMS) techniques. KEML studies were carried out in a large temperature range (398-567) K by using effusion orifices with 0.3, 1, and 3 mm diameters. The vapor pressures so measured revealed no kinetically hindered vaporization effects and provided second-law vaporization enthalpies at the mean experimental temperatures in close agreement with literature. By exploiting the large temperature range covered, the heat capacity change associated with vaporization was estimated, resulting in a value of -66.8 J K(-1) mol(-1), much lower than that predicted from calorimetric measurements on the liquid phase and theoretical calculations on the gas phase. The conversion of the high temperature vaporization enthalpy to 298 K was discussed and the value Δ(l)(g)H(m)(298 K) = (128.6 ± 1.3) kJ mol(-1) assessed on the basis of data from literature and present work. Vapor pressure data were also processed by the third-law procedure using different estimations for the auxiliary thermal functions, and a Δ(l)(g)H(m)(298 K) consistent with the assessed value was obtained, although the overall agreement is sensitive to the accuracy of heat capacity data. KEMS measurements were carried out in the lower temperature range (393-467) K and showed that the largely prevailing ion species is BMIm(+), supporting the common view of BMImNTf2 vaporizing as individual, neutral ion pairs also under equilibrium conditions. By monitoring the mass spectrometric signal of this ion as a function of temperature, a second-law Δ(l)(g)H(m)(298 K) of 129.4 ± 7.3 kJ mol(-1) was obtained, well consistent with KEML and literature results. Finally, by combining KEML and KEMS measurements, the electron impact ionization cross section of BMIm(+) was estimated.

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Vapor pressures and standard molar enthalpies, entropies, and Gibbs free energies of sublimation of 2,4- and 3,4-dinitrobenzoic acids

Cited by 21 publications

References 21 publications

Vapor pressures and standard molar enthalpies, entropies and Gibbs energies of sublimation of three 4-substituted acetanilide derivatives

Vapor pressures and standard molar enthalpies, entropies and Gibbs energies of sublimation of three 4-substituted acetanilide derivatives

Are the Sublimation Thermodynamics of Organic Molecules Predictable?

Vaporization of the prototypical ionic liquid BMImNTf2 under equilibrium conditions: a multitechnique study

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