Comment/Reply pubs.acs.org/jced
Cite This: J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Comment on “Solubility Measurement and Thermodynamic Modeling of N‑(4-Methylphenyl‑Z‑3-chloro-2(phenylthio)propenamide in 12 Pure Solvents at Temperatures Ranging from 278.15 to 318.15 K” William E. Acree, Jr.,*,† Brittani Churchill,† and Michael H. Abraham‡ †
Department of Chemistry, 1155 Union Circle Drive #305070, University of North Texas, Denton, Texas 76203, United States Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ, U.K.
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ABSTRACT: The calculated modified Apelblat model curve-fit parameters reported in the paper by de Souza and co-workers were found not to describe the observed solubility data. Our back-calculated solubilities differed significantly from the experimental data given in the authors’ published paper. The experimental solubility data are reanalyzed in accordance with the modified Apelblat model, and the curve-fit parameters are recalculated.
I
n a recent paper published in the Journal of Chemical and Engineering Data de Souza and co-workers1 reported the solubility of N-(4-methylphenyl-Z-3-chloro-2-phenylthio)propenamide dissolved in 12 organic monosolvents (acetone, acetonitrile, butanone, ethyl acetate, methyl acetate, methyl tert-butyl ether, tetrahydrofuran, toluene, 1,2-dichloroethane, 2-propanol, 2-methyltetrahydrofuran, and 2-methyl-2-butanol) from 278.15 to 318.15 K. Solubilities were determined by a gravimetric method of analysis that involved transferring a aliquot of the clear saturated solution into a preweighed vial. The vial with contents was then weighed and placed in a vacuum drying oven at 323.15 K for 24 h. After the solvent had evaporated, the vial with solid residue was weighed. The solubility was calculated from the mass of the solid residue and the mass of the saturated solution taken for analysis. One of the expressions the authors used to describe the variation of the solubility with temperature was the modified Apelblat equation: ln C (grams/kg solvent) = aA + (bA /T) + cA ln T
We calculate a solubility of C = 1.391 grams per kilogram of solvent, which differs significantly from the observed solubility of C = 247.80 grams per kilogram of solvent that is given in the second column of Table 2 of ref 1. Similar errors were noted in the authors’ calculated curve-fit parameters for other organic solvents. Given the large difference between the experimental solubilities and values back-calculated based on the authors’ curve-fit parameters we decided to recalculate the curve-fit parameters for the modified Apelblat model. Our recalculated curve-fit parameters are given in Table 1 of this commentary. By substituting the numerical values in Table 1 into eq 1, ln C = −520.60 + (20050.5/298.15) + 80.536 ln 298.15 (4)
Table 1. Calculated Modified Apelblat Model Curve-Fit Parameters for Describing the Solubility of N-(4Methylphenyl-Z-3-chloro-2-(phenylthio))propenamide in Select Organic Solvents
(1)
where C is the solubility of N-(4-methylphenyl-Z-3-chloro-2phenylthio)propenamide in the respective solvent expressed in grams of dissolved solute per kilogram of solvent, and T is the temperature of the saturated solution. The curve-fit parameters (aA, bA, and cA) were determined by regression analysis of the observed solubility data in accordance with eq 1. Our purpose is not to criticize the excellent work of de Souza and co-workers,1 but rather to point out to journal readers that the authors’ calculated curve-fit parameters for eq 1 do not describe the observed solubility data given in Table 2. We calculate the solubility of N-(4-methylphenyl-Z-3-chloro-2phenylthio)propenamide in acetone at T = 298.15 K by substituting the authors’ calculated curve-fit parameters from Table 3 of ref 1 into eq 1:
organic solvent
aA
bA
cA
acetone acetonitrile butanone ethyl acetate methyl acetate tert-butyl methyl ether tetrahydrofuran toluene 1,2-dichloroethane 2-methyl-2-butanol 2-methyltetrahydrofuran 2-propanol
−520.60 −519.80 −244.04 −324.98 −149.89 −316.48 −212.61 −392.06 −166.11 −733.40 −411.94 −349.17
20050.5 19155.4 8072.66 11359.6 3533.6 11502.2 7647.9 13939.1 4429.9 28133.9 15827.9 12464.8
80.536 80.732 39.068 51.230 25.111 49.442 33.952 61.435 27.522 112.594 63.968 54.470
ln C = −512 + (19400/298.15) + 78.5006 ln 298.15 Received: March 28, 2018 Accepted: July 2, 2018
(2)
ln C = −512 + 65.07 + 447.26 © XXXX American Chemical Society
(3) A
DOI: 10.1021/acs.jced.8b00256 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
Journal of Chemical & Engineering Data ln C = −520.60 + 67.25 + 458.86
Comment/Reply
(5)
we calculate a value of C = 247.15 grams per kilogram for the solubility of N-(4-methylphenyl-Z-3-chloro-2-phenylthio)propenamide in acetone at T = 298.15 K. The experimental value given by de Souza and co-workers1 is C = 247.80 grams per kilogram.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Fax: 940-565-4318. ORCID
William E. Acree, Jr.: 0000-0002-1177-7419 Michael H. Abraham: 0000-0002-4579-8621 Notes
The authors declare no competing financial interest.
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REFERENCES
(1) de Souza, B.; Keshavarz, L.; Steendam, R. R. E.; Dennehy, O. C.; Lynch, D.; Collins, S. G.; Moynihan, H. A.; Maguire, A. R.; Frawley, P. J. Solubility measurement and thermodynamic modeling of N-(4methylphenyl-Z-3-chloro-2-(phenylthio))propenamide in 12 pure solvents at temperatures ranging from 278.15 to 318.15 K. J. Chem. Eng. Data 2018, 63, 1419−1428.
B
DOI: 10.1021/acs.jced.8b00256 J. Chem. Eng. Data XXXX, XXX, XXX−XXX
