Synthesis and characterization of some transition metal complexes of N'- [(E)-(1H-indol-2-yl) methylidene]pyridine-4-carbohydrazide

Abstract

N'-[(E)-(1H-indol-2-yl)methylidene]pyridine-4-carbohydrazide was prepared by refluxing indole-2- carbaldehyde and isonicotinic hydrazide in ethanol for 4 hrs. Fe³⁺, Co²⁺ and Cu²⁺ complexes of the hydrazone ligand were similarly prepared and the compounds characterized spectrophotometrically. The melting point and conductivities of the ligand and complexes were recorded. The asymmetric hydrazone and the metal complexes obtained showed melting points/ decomposition temperature range 156 - >300 ^oC. Two ligands was found to coordinate to the metal centre via the carbonyl O and azomethine N along with two chloride ions giving rise to octahedral geometry. Ligand and complexes are insoluble in water, ethanol and other common organic solvents but soluble in DMSO and DMF. Molar conductivity values obtained (2.55-7.23 cm^-2mol^-1) shows they are nonelectrolytes in solution.

Keywords: Asymmetric, Bioactive, Hydrazone, indole, Isoniazid