Skip to main content
SpringerLink
Log in

Acid-base equilibria of some pyridinol derivatives in binary water/organic solvent systems

Säure-Basen-Gleichgewichte einiger Pyridinolderivate in binären Systemen aus Wasser und organischen Lösungsmitteln

  • Anorganische Und Physikalische Chemie
  • Published:
Monatshefte für Chemie / Chemical Monthly Aims and scope Submit manuscript

Summary

pK a values of 2-hydroxy 3-pyridinol (HHP), 2-mercapto 3-pyridinol (MHP), and 2-carboxy-3-pyridinol (CHP) were determined by potentiometric titration in water/organic solvent mixtures containing 20 mole% of organic solvent at 25±0.1 °C and 0.1M ionic strength (KNO3) applying an empiricalpH correction for mixed aqueous solvents. The influence of the organic solvents on the dissociation constants and tautomeric equilibria of the pyridinol derivatives is discussed. The effect of the molecular structure of the compounds onpK a is also explained. Titrations of a mixture of two weak diprotic acids (HHP andCHP) in a water/dimethylsulphoxide medium containing 20 mole% organic solvent at constant ionic strength were evaluated using theGran method.

Zusammenfassung

DiepK a-Werte von 2-Hydroxy-3-pyridinol (HHP), 2-Mercapto-3-pyriodinol (MHP) und 2-Carboxy-3-pyridinol (CHP) wurden durch potentiometrische Titration in wäßrigen Systemen mit 20 mol% organischem Lösungsmittelanteil bei 25±0.1 °C und einer lonenstärke von 0.1M KNO3 unter Anwendung einer empirischenpH-Korrektur für Lösungsmittelgemische bestimmt. Der Einfluß der organischen Lösungsmittel auf die Dissoziationskonstanten und die tautomeren Gleichgewichte der untersuchten Verbindungen und der Einfluß der molekularen Strukturen auf diepK a-Werte werden diskutiert. Die Titration eines Gemisches von zwei schwachen zweibasigen Säuren (HHP undCHP) in Wasser/Dimethylsulfoxid bei konstanter Ionenstärke wurde mit Hilfe derGranschen Methode ausgewertet.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Saleh M. S., Idriss K. A., Abu-Bakr, M. S., Hashem E. Y. (1992) Analyst117: 1003

    Google Scholar 

  2. Saleh M. S. (in course of publication).

  3. Idriss K. A., Saleh M. S., Sedaira H., Seleim M., Hashem E. Y. (1991) Monatsh. Chem.122: 507

    Google Scholar 

  4. Manning P. C. (1966) Can. J. Chem.44: 1471

    Google Scholar 

  5. Fowles G. W., Matthews R. W., Walten R. A. (1968) J. Chem. Soc.A: 1108

    Google Scholar 

  6. Azoo J. A., Reginald G. R., Gupta K. (1975) J. Chem. Soc.C: 1975

    Google Scholar 

  7. Shelke D. N., Jahagirdar D. V. (1979) J. Inorg. Nucl. Chem.41: 929

    Google Scholar 

  8. Aruga R. (1979) J. Inorg. Nucl. Chem.41: 845

    Google Scholar 

  9. Keith B., Ramesh P., Egon M. (1982) Polyhedron1: 269

    Google Scholar 

  10. Couturier Y., Petifaux Ch. (1984) Bull. Soc. Chim. Fr. 72

  11. Saleim M., Idriss K. A., Saleh M. S., Sedaira H. (1987) Analyst112: 1685

    Google Scholar 

  12. Napoli A., Magri A. L. (1989) Ann. Chim. (Rome)77: 783

    Google Scholar 

  13. Bucci R., Carunchio V., Girelli A. M., Messina A. (1985) Polyhedron4: 1433

    Google Scholar 

  14. Idriss K. A., Seleim M. M., Saleh M. S., Hashem E. Y. (1993) Bull. Fac. Sci., Assiut Univ.,22: 109

    Google Scholar 

  15. Magda S., Saleh K. A., Idriss H. A., Azab, Hashem E. Y. Solution Chem. (in press)

  16. Gutmann V. (1968) Coordination Chemistry in Non-aqueous Solutions, Springer, New York

    Google Scholar 

  17. Logowski J. J. (ed.) (1966) The Chemistry of Non aqueous Solvents, Vol. 1. Academic Press, New York

    Google Scholar 

  18. Burger K. (1983) Solvation, Ionic and Complex Formation Reactions in Non-aqueous Solvents. Elsevier, Amsterdam

    Google Scholar 

  19. Gran G. (1952) Analyst77: 661

    Google Scholar 

  20. Guenther W. (1975) Chemical Equilibrium. Plenum Press, New York, p. 106

    Google Scholar 

  21. Serjeant E. P. (1985) Potentiometry and Potentiometric Titrations. Wiley-Interscience, New York, p. 338

    Google Scholar 

  22. Robinson R. A., Stokes R. H. (1959) Electrolyte Solutions, 2nd ed. Butterworths, London, p. 230

    Google Scholar 

  23. Bacarella A. L., Grunwald E. W., Marshall H. P., Purlee L. L. (1955) J. Org. Chem.20: 747

    Google Scholar 

  24. Albert A., Serjeant L. P. (1962) Ionization constants of Acids and Bases. Methuen, London, p. 58

    Google Scholar 

  25. Deligny C. L., Luykx P. E. M., Rehback M., Wieneke A. A. (1960) Rec. Trav. Chim. Pays-Bas.79: 713

    Google Scholar 

  26. Coetzee J. F., Ritchie C. D. (1969) Solute-Solvent interactions. Marcel Dekker, New York, p. 221

    Google Scholar 

  27. Gutmann V. Electrochim. Acta (1976)21: 661; Chimia (1977)31: 1

    Google Scholar 

  28. Elguero J., Marzin C., Katritzky A. R., Linda P. (1976) The Tautomerism of Heterocycles (Edited by A. R. Katritzky). Academic Press, New York

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Chemistry Department, Faculty of Science, Assiut University, Assiut, Egypt

    M. S. Saleh

Authors
  1. M. S. Saleh
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Saleh, M.S. Acid-base equilibria of some pyridinol derivatives in binary water/organic solvent systems. Monatsh Chem 126, 377–384 (1995). https://doi.org/10.1007/BF00813199

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00813199

Keywords

Search

Navigation