Abstract

STUDY OF THERMODYNAMIC PARAMETERS FOR AZO DYES DERIVED FROM SUBSTITUENTS OF 2, 4-DIHYDROXYACETOPHENONE

Dunia Butrus Toma Al-Bakzo* and Mohammad Mahmoud Hussein Al-Niemi

ABSTRACT

The study included the synthesis of six Schiff basses derived from the mother ketone named 2, 4-dihydroxy acetophenone with an appropriate primary aromatic amines as aniline and its para substituents. The substituents had chosen to act donor or acceptor property as (CH3O, CH3, NO2, OH, CO2H) groups. The structures of these Schiff bases were confirmed by physical method, using U.V. and IR spectra beside the melting points. The first steps were the estimation of stability constant values of azo dyes formed by reactions of Schiff bases with the diasonium reagent derived from sodium salt of sulphanilic acid at PH =9. The formula of the dyes under this paper were confirmed by using the mole ratio method which lead to the formation of (1: 1) reagent: Schiff bases formula for all the dyes. The second steps study the effect of temperature change on thermodynamic parameters at five different temperatures in the range (273-313) Kelvin at basic medium. The components of the azo dyes and their thermodynamic parameters were calculated by the spectrophotometric method using U.V spectra.

Keywords: Azo dyes, Schiff bases, 2, 4- di hydroxy acetophenone, thermodynamic parameters, stability, mole ratio.