• Potentiometric studies on the complexation equilibria involving diacetylmono(lepidyl) hydrazone and bivalent metal ions in aqueous ethanolic medium

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      https://www.ias.ac.in/article/fulltext/jcsc/103/01/0017-0024

    • Keywords

       

      Stability constants; thermodynamic parameters; diacetylmono(lepidyl) hydrazone; bivalent ions

    • Abstract

       

      The ligand diacetylmono(lepidyl) hydrazone(DALH) has been synthesized in four steps and characterized by melting point, thin layer chromatography, elemental analysis, NMR and IR. Complex formation between transition metal ions Mn(II), Pb(II), Cd(II), Co(II), Ni(II), Cu(II), U02(II) and DALH has been investigated by potentiometric measurements of hydrogen ions liberated on complexation at 25, 30, 40 and 50±0·5°C in 0·02, 0·05, 0·1 and 0·2 M (NaCl) ionic strength and in 75% ethanol-water medium. From the potentiometric titration curves dissociation constants of the ligand and stability constants of its complexes have been determined. Using these stability constants, thermodynamic parameters such as free energy changes (ΔG), enthalpy changes (ΔH) and entropies (ΔS) of complex formation have calculated and reported. Thermodynamic stability constants (logK10) have also been reported. The ligand field stabilization energy (δH) has been calculated for the first row transition metals which is in good agreement with the theory.

    • Author Affiliations

       

      B S Garg1 Manjurani Choudhury1 Ranjana Dixit1

      1. Department of Chemistry, University of Delhi, Delhi - 110007, India
    • Dates

       
  • Journal of Chemical Sciences | News

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