Synthesis, Magnetic Susceptibility, Thermodynamic Study and Bio-Evaluation of Transition Metal Complexes of New Schiff Base Incorporating INH Pharmacophore

Transition metal complexes of synthesized organic ligands incorporating INH were successfully investigated by potentiometrically. The stability constants of these binary complexes were evaluated and order of stability constant found as above Zn(II) > Co(II) > Ni(II) > Mn(II) > Cu(II). Magnetic moment value clearly indicates that newly prepared transition metal complexes of N-[(E)-(2-Hydroxyphenyl)methylen]isonicotinohydrazid are paramagnetic in nature. The stability constants for complexes decrease with an increasing temperature, indicating that the composition equilibrium is exothermic in nature. Also the change in enthalpy (Delta H) and change in Gibb's free energy (Delta G) were negative for all of the systems which suggested that all of the reactions were exothermic. The change in entropy (Delta S) found positive for most of the complexes which indicate in metal-ligand binding process is entropy favourable. Metal complexes of organic ligand shows moderate antibacterial activity against gram positive and gram negative bacteria. It also possesses prominent antifungal activity for Nickel (II) complex. Biological evaluation results of transition metal complexes show superior pharmacological applications as compared to organic ligand.