Abstract
Precise thermodynamic ionization constants K for 3-nitrophenol, 3,4-dichlorophenol, and 4-cyanophenol have been obtained in 1,4-dioxane-water mixtures (0–70% volume fraction in dioxane) at 25°C using a potentiometric method. The same information for another twelve cationic, neutral, and anionic phenols were taken from the literature. Three different methods were used to study the effects of the solvents on the ionization constants: one involves a single polarity parameter, E T(30); the next involves the Kamlet–Taft multiparametric method; and the last involves the preferential solvation model. The pK values follow the preferential solvation model, but the parameters obtained are highly correlated. Using the data for the phenol molecule as reference, a linear correlation between ΔpK and E T(30) has been used to develop a new method of obtaining pK values for any binary solvent composition, with only the pK in water known. The pK(s) values correlate with the molecular parameters for the dipolarity/polarizability of the solvent π* and its hydrogen-bond donor ability α. The preferential solvation parameter, f 12/1, correlates with the parameter for the hydrogen-bond donor ability of the solvent. All the phenols follow Hammett's equation and the reaction constants have been calculated for the different water–dioxane mixtures.
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REFERENCES
J. G. Dawber, J. Ward, and R. A. Williams, J. Chem. Soc., Faraday Trans. I 84, 713 (1988).
Y. Marcus, J. Chem. Soc., Perkin Trans. II, p. 1751 (1994).
P. Chatterjee, A. K. Laha, and S. Bagchi, J. Chem. Soc., Faraday Trans. 88, 1675 (1992).
R. D. Skwierczynski and K. A. Connors, J. Chem. Soc., Perkin Trans. II, 467 (1994).
J. Ortega, C. Ràfols, E. Bosch, and M. Rosés, J. Chem. Soc., Perkin Trans. II, 1497 (1996).
C. Reichardt, Chem. Rev. 94, 2319 (1994).
C. Reichardt, in Solvents and Solvent Effects in Organic Chemistry, 2nd ed. (VCH, Weinheim, New York, 1988).
E. Casassas, G. Fonrodona, and A. de Juan, J. Solution Chem. 21, 147 (1992).
E. Casassas, G. Fonrodona, and A. de Juan, Inorg. Chim. Acta 187, 187 (1991).
J. G. Dawber, J. Chem. Soc., Faraday Trans. 86, 287 (1990).
M. Rosés, F. Rived, and E. Bosch, J. Chem. Soc., Faraday Trans. 89, 1723 (1993).
E. Bosch, C. Ràfols, and M. Rosés, Anal. Chim. Acta 302, 109 (1995).
E. Bosch and M. Rosés, J. Chem. Soc., Faraday Trans. 88, 3541 (1992).
M. Rosés, C. Ràfols, J. Ortega, and E. Bosch, J. Chem. Soc., Perkin Trans. II, 1607 (1995).
M. J. Kamlet and R. W. Taft, J. Am. Chem. Soc. 98, 377, 2886 (1976).
M. J. Kamlet, J.-L. M. Abboud, and R. W. Taft, J. Am. Chem. Soc. 99, 6027 (1977).
M. J. Kamlet, J.-L. M. Abboud, M. H. Abraham, and R. W. Taft, J. Org. Chem. 48, 2877 (1983).
M. Cortijo, J. Llor, and J. M. Sánchez-Ruiz, J. Biol. Chem. 263, 17960 (1988).
J. M. Sanchez-Ruiz, J. Llor, and M. Cortijo, J. Chem. Soc., Perkin Trans. II, 2047 (1984).
L. G. van Uitert and C. E. Haas, J. Am. Chem. Soc. 75, 451 (1953).
L. G. van Uitert and W. C. Fernelius, J. Am. Chem. Soc. 76, 5887 (1954).
J. Llor, J. M. Sanchez-Ruiz, and M. Cortijo, Acta Cient. Comp. 22, 231 (1985).
J. J. Christensen, L. D. Hansen, and R. M. Izatt, Handbook of Proton Ionization Heats and Related Thermodynamics Quantities, (Wiley-Interscience, New York, 1976).
D. D. Perrin, B. Dempsey, and E. P. Sarjeant, p K a Prediction for Organic Acids and Bases (Chapman and Hall, London, 1981).
R. A. McClelland and M. Coe, J. Am. Chem. Soc. 105, 2718 (1983).
J.-L. M. Abboud, R. W. Taft, and M. J. Kamlet, Bull. Chem. Soc. Jpn. 55, 603 (1982).
Y. Marcus, Ion Solvation (Wiley, Chichester, 1985).
Y. Marcus, Chem. Soc. Rev. 22, 409 (1993).
Y. Marcus, J. Chem. Soc., Faraday Trans. I 85, 385 (1989).
R. W. Taft, J.-L. M. Abboud, M. J. Kamlet, and M. H. Abraham, J. Solution Chem. 14, 154 (1985), and references therein.
M. H. Abraham, P. L. Grellier, J.-L. M. Abboud, R. M. Doherty, and R. W. Taft, Can. J. Chem. 66, 2673 (1988).
C. Laurence, P. Nicolet, M. T. Dalati, J.-L. M. Abboud, and R. Notario, J. Phys. Chem. 98, 5807 (1984).
H. Bartnicka, I. Bojanowska, and M. K. Kalinowski, Aust. J. Chem. 46, 31 (1993).
C. D. Johnson, The Hammett Equation (Cambridge University Press, London, 1973).
C. Hansch, A. Leo, and R. W. Taft, Chem. Rev. 91, 165 (1991).
D. V. Jahagirdar, D. N. Sheike, and R. G. Deshpande, J. Chem. Soc., Perkin Trans. II, 1513 (1977).
M. Fujio, R. T. McIver, Jr., and R. W. Taft, J. Am. Chem. Soc. 103, 4017 (1991).
M. Mashima, R. T. McIver, Jr., R. W. Taft, F. G. Bordwell, and W. N. Olmstead, J. Am. Chem. Soc. 106, 2717 (1984).
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Llor, J. A Correlation Between Solvatochromic Solvent Polarity Parameters and the Ionization Constants of Various Phenols in 1,4-Dioxane–Water Mixtures. Journal of Solution Chemistry 28, 1–20 (1999). https://doi.org/10.1023/A:1021795106493
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DOI: https://doi.org/10.1023/A:1021795106493