Summary
Dicoumarol, 3,3′-methylenebis-(4-hydroxycoumarine) (I), is well known as an effective anticoagulant agent. The electrochemical behaviour of (I) and some its derivatives, (3,3′-ethylenebis-(4-hydroxycoumarine) (II),3,3′-propylenebis-(4-hydroxycoumarine) (III), 3,3′-isobutylenebis-(4-hydroxycoumarine) (IV), 3,3′-benzylidenebis-(4-hydroxycoumarine) (V), has been investigated in DMF solutions containing 0.5 F (Et4N)ClO4 as supporting electrolyte. At a D.M.E. a two-step reduction takes place with every compound investigated. The first step is relative to the discharge of solvated H+, the second to the hydrogen in the undissociated species HB−. The acidic strength of various HB− in DMF has been evaluated from spectrophotometric determinations of the constants (relative to the concentrations) of the equilibrium: HB− + S ⇆ HS+ + B2−.
The half-wave potential values for the discharge of solvated H+ originated by compounds II–V are coincident, or slightly more positive, than the values for the solvated H+ ion issuing from HClO4 or dicoumarol. The values of E 1/2″ for the hydrogen reduction in the HB− anion of compounds II–V are arranged in the same order as the pK values of the second dissociation step.
These results are discussed on the basis of specific variations of the local dielectric constant of the solvent. According to Sanfeld and Hurwitz such deviations may cause the ion pair formation constants or the weak acid dissociation constants, to undergo some variations from their bulk values.
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
A. Inesi and L. Rampazzo, Electrochim. Acta in press.
A.J. Parker, Quarterly Revs. 16, 171 (1962).
H.E. Zaugg and A.D. Schaefer, Anal. Chem. 36, 2121 (1964).
B.W. Clare, D. Cook, E.C.F. Ko, Y.C. Mac and A.J. Parker, J. Amer. Chem. Soc. 88, 1911 (1966).
A.B. Thomas and E.G. Rochow, J. Amer. Chem. Soc. 79, 1843 (1957).
C.C. Lee, L.W. Trevoy, L.B. Jaques and J.W.T. Spinks, Can. J. Research, 28 B, 170 (1950).
M.A. Stahmann, J. Wolf and K.P. Link, J. Amer. Chem. Soc. 65, 2286 (1943).
W.R. Sullivan, C.F. Hebner, M.A. Stahmann and K.P. Link, J. Amer. Chem. Soc. 65, 2288 (1943).
T. Fujnaga, K. Izutsu and K. Takaoka, J. Electroanal. Chem. 12, 203 (1966).
R. Mnouchek, Cesk, Farm., 17, 173 (1968).
R.G. Bates, “Determination of pH”, John Wiley and Sons, Inc., New York, N.Y., 1963. Chapter 7.
A. Sanfeld, Introduction to the Thermodynamics of Charged and Polarized Layers, Interscience Publ., New York, 1968
H.D. Hurwitz, A. Sanfeld, A. Steinchen-Sanfeld, Electrochim. Acta 9, 928 (1964).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1971 Springer Basel AG
About this chapter
Cite this chapter
Inesi, A., Rampazzo, L. (1971). Electrochemical Behavior of 3,3′-Methylenebis-(4-hydroxycoumarine) (dicoumarol) Derivatives in DMF. In: Milazzo, G., Jones, P.E., Rampazzo, L. (eds) Biological Aspects of Electrochemistry. Experientia Supplementum, vol 18. Birkhäuser, Basel. https://doi.org/10.1007/978-3-0348-5848-9_30
Download citation
DOI: https://doi.org/10.1007/978-3-0348-5848-9_30
Publisher Name: Birkhäuser, Basel
Print ISBN: 978-3-0348-5850-2
Online ISBN: 978-3-0348-5848-9
eBook Packages: Springer Book Archive