The Influence of pH and Temperature on Tautomerism Reactions of Some Aromatic Mono and Bi Schiff Bases

Abstract

The aims at investigation the tautomerism reaction of mono and bi aromatic
Schiff bases by actions of different values of pH,s and temperatures. The pH under
study was chosen in a range between 4-10.
Experiments prove the existence of Schiff bases under study, as tautomeric
equilibrium mixture of different ratios of keto and enol forms , as well as , the
formations of nitrilium and phenoxonium ions in acidic and basic media respectively.
Equilibrium constants K for the tautomerism reaction are evaluated at a temperature
range between 298-338k. the last shows an inverse relationship between K and T
which facilitates the evaluation of thermodynamic parameters. Finally evidence for
supporting the tautomerism reaction is mentioned and disussed.