The Effect of Temperature and Thermodynamic Parameters on the Ionization Constants of Some Imines Derived from Vanillin with substituted aniline

  • Rawaa Daoud Sulaiman
  • Zaheda Ahmed Najim

Abstract

This work presents a method for the preparation of imine compounds including Schiff bases derived from vanillin with aniline, o-nitroaniline, o-tolidene and o-chloroaniline. Compounds' structures of the prepared compounds were confirmed by physical methods like melting point, infrared spectroscopy (IR), electronic spectroscopy (U.V), and nuclear magnetic resonance spectroscopy (NMR).


The ionization constants of the imine nitrogen proton Ka1 and the phenol hydroxyl group proton Ka2 were determined using the spectrometric titration method at five temperatures including 293,298,303,308 and 313K in a buffer solution medium. The thermodynamic of ionization for imines confirm that ionization reactions in these imines are accompanied by an increase of parameters ∆Gº and ∆Hº. These mean that ionization reactions in these imines are non-spontaneous and endothermic respectively. ∆Sº values of ionization reactions estimated have a negative and a positive signs.


 


http://dx.doi.org/10.25130/tjps.27.2022.050

Published
Sep 13, 2022
How to Cite
SULAIMAN, Rawaa Daoud; NAJIM, Zaheda Ahmed. The Effect of Temperature and Thermodynamic Parameters on the Ionization Constants of Some Imines Derived from Vanillin with substituted aniline. Tikrit Journal of Pure Science, [S.l.], v. 27, n. 4, p. 31-38, sep. 2022. ISSN 2415-1726. Available at: <https://tjps.tu.edu.iq/index.php/j/article/view/1331>. Date accessed: 03 oct. 2022. doi: http://dx.doi.org/10.25130/j.v27i4.1331.
Section
Articles