The Titrations of some new thizole derivatives in non aquous media

IV SUMMARY Master Thesis THE TITRATIONS OF SOME NEW THIAZOLE DERIVATIVES IN NON-AQUOUS MEDIA İbrahim YILMAZ Fırat University Graduate School of Natural and Applied Sciencies Department of Chemistry 1998, Page: 60 In this work, some Schiff bases have been synthesized, from the reaction of benzaldehyde itself and 2-hydroxy, 4-hydroxy, 2-hydroxy-3-metoxy, 4-bromo, 4-(dimethyIamino) benzaldehydes, naphtaldehyde and 2 - hydroxy - 1 - naphtaldehyde, and 4 - phenyl - 2 - aminothiazole and 4 - p-tolil - 2 -aminothiazole. The Schiff bases obtained were titrated potentiometrically both acids and bases in non- aquous media. In the titration of these Schiff bases as base, nitrobenzene was used as solvent and perchloric acid solution as titrant which is prepared in nitrobenzene solvent. On the other hand, in the titration of Schiff bases as base, pyridine was used as solvent and tetrabuthylammonium hydroxide, which is prepared in 2-propanole, as titrant. In the titrations carried out in nitrobenzene and pyridine mediums, half-neutralization (h.n.p.) potentials which is an indicator of acidity and basicity of Schiff bases, were obtained. Titration graphs were obtained by plotting volume of titrant solution (mL) used in titrations against potentials which are obtained every addition of titrant. From the titration curves, half-neutralization potentials were obtained and these potantials were used in interpretation of the basicity and acidity of Schiff bases. On the other hand, the data obtained were also used in the investigation of the effects of functional groups on the acidity and basicity of Schiff bases. Results which is inferred from the Tables arranged according to the titrations performed in nitrobenzene medium, can be interpreted as follows;V 1. When effect of aldehyde group on the basicity of Schiff bases is inspected, is found that the phenyl group is more basic than napthyl group. 2. -OH group bound in o-position with aldehyde group is decreased the basicity of Schiff bases. 3. -Br bound to benzene in p-position according to aldehyde group is decreased the basicity of Schiff bases. 4. It is observed the alkyl groups is increased the sasicity of Schiff bases. Results of tables arrange from of the titrations performed in pyridine medium are ass follows. 1. Effect of aldehyde component on the acidity of Schiff bases, naphtyl group is more acidic than phenyl group. 2. The -OH groups bound to the molecule in o-position according to the aldehyde is increased the acidity of Schiff bases, on the contruary of literature, alkyl groups are increased the acidity of Schiff bases. KEY WORDS : Non-aquous media, potentiomctric titrations, thiazole derivatives, Schiff bases