Abstrait

Influence of buffers and temperatures in tautomerism reactions of p-aminobenzylidene o-hydroxyaniline

A.S.P.Azzouz, A.B.N.Al-Dabagh

As an answer of unsuccessful dye formation by reaction of paminobenzylidene- o-hydroxyaniline (I) with diazotied sulphanilic acid mixture, the tautomerism reactions in such molecule were found to be the correct reason.Moleule I was prepared by a standard method, its structure was confirmed by the measurements of melting point, beside UV and IR spectra. Themain aimof this investigation was dealwith tautomerismstudy in I by the aid of U.V spectrum. Some factors affecting on equilibrium constants K1 and K2 of tautomerism reactions happen in I were discussed. These included influence of different buffers in the range of pH4-10 and different temperatures were studied. Finally, the thermodynamic parameters of tautomerismreactionsÄGº, ÄHº and ÄSº were calculated and discussed.