Synthesis, Characterization, Equilibrium Studies and Antibacterial Studies of Co(II) Complex with Schiff Base Ligand Derived from Pyridoxal and 2,4-Dichlorobenzohydrazide

The Co(II) metal (M) complex of 2,4-dichloro-N-((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)benzohydrazide (L) was synthesized and characterized by elemental analysis, molar conductance, magnetic moment measurements, LC-MS, IR, TGA and UV spectral studies. Irving-Rossetti titration method was employed to determine the acid dissociation constant of ligand and the stability constant of Co(II) complex in 70% (v/v) DMF-water medium at 0.1 M KNO₃ ionic strength and 303K temperature. The spectroanalytical data indicate the composition of the complexes to be 1:2 (ML₂) with octahedral geometry. The ligand and the complex were screened for their antibacterial activity against Gram positive and Gram negative bacteria using agar well diffusion method.