Determination of Metal-Ligand Stability Constant of Transition Metal Complexes with Pharmacologically Active Ligand N-[(E)-(2- Nitrophenyl)methylen]isonicotinohydrazid

Proton–ligand association constants of organic ligand N-[(E)-(2-Nitrophenyl) methylen]isonicotinohydrazid with Mn (II), Co (II), Ni (II), Cu (II) and Zn (II) metal ions have been studied by pH-metric technique at 27±1Cͦ in 70%(v/v) ethanol – water medium at 1M (NaClO4) ionic strength. Organic ligand was synthesized by condensation of equimolar mixture of Anti-mycobacterial agent with aromatic aldehyde. The reaction progress and purity of organic ligands were confirmed by thin layer chromatography. Formation of organic ligands was confirmed with the help of MP, IR, H NMR, C NMR and elemental analysis. The stability constants of these binary complexes were evaluated and order of stability constant found as Zn (II) >Ni (II) > Cu (II) > Mn (II) > Co (II).