doiSerbia

Physico-chemical studies of some aminobenzoic acid hydrazide complexes

El Abd Wahed M.G. (Faculty of Science, Zagazig University, Zagazig, Egypt)
El Abd Wanees S. (Faculty of Science, Zagazig University, Zagazig, Egypt)
El Gamel M. (Faculty of Science, Zagazig University, Zagazig, Egypt)
El Abd Haleem S. (Faculty of Science, Zagazig University, Zagazig, Egypt)

The stability constants and related thermodynamic functions characterizing the formation of divalent Ni, Cu, Zn, Cd and Hg complexes with o- and p-aminobenzoic acid hydrazide were determined potentiometrically at different temperatures. The formations of the complexes are endothermic processes. The formed bonds are mainly electrostatic. Conductometric titration was carried out to determine the stoichiometry and stability of the formed complexes. The structures of complexes were characterized by their IR, 1H-NMR and 13C-NMR spectra, as well as X-ray diffractograms. The coordination process takes place through the carbonyl group and the terminal hydrazinic amino group. The thermal stability of the complexes was followed in the temperature range 20–600 ºC.

Keywords: potentiometry, conductometry, stability constants, thermodynamic parameters, structure and thermal stability of complexes