SPECTRAL BEHAVIOUR AND CHELATING TENDENCIES OF SOME IMIDAZOLE AND PYRIMIDINE AZO DYES

Abstract

The present work represents a study of the spectral behaviour and chelating tendencies of some azo benzimidazoles and azo pyrimidines. The compounds under investigations are :

2(X-phenyl azo)- 2.-cyanomethyl benzimidazoles (I.-V.).

2(X-phenyl azo}2-cyanomethyl-1- methyl benzimidazoles (lb-Vb).

5(X-phenyl azo) barbituric acids (L:-Vc)•

5(X- phenyl azo)-2-amino- 4,6- dihydroxy pyrimidines ( Id- Vd). Where

X =-H (I.,Ib Jc ,); o-OH (II.,IIt>,IIc,l ); p-OH (III., Illb, Illc, Illd); m-OH,.p-COOH (IV.,IVb, IVc,IVd);p- NOiV., Vb, Vc, Vd)

The thesis contains two main parts. In the first part, the electronic absorption spectra of the above compounds are recorded in pure organic solvents of different polarities, in mixed organic solvents and in aqueous buffer solutions. This is performed with the aim to assign the different absorption bands and collect more informations concerning the structure of these types of compounds. The possible interactions of these compounds with solvent molecu­ les have also been investigated. In addition the work is made to determine the ionization constant of the studied compound and examined the effect of their molecular structure.

The second part of this thesis, deals with the study of 2+ coordination tendency ofNb(V), Zr(IV), Th(IV), La(III) and U0 2 ions and some arylazo benzimidazoles and arylazo pyrimidines viz.,

2- phenyl azo-2- cyanomethyl benzimidazole I.,(LI).