Synthesis and Characterization of Mixed Complexes of Co (II) and Fe (II)

Mixed ligand complexes of Co (II) and Fe (II) with salicylic acid and nicotinamide were synthesized. The complexes were characterized by some standard methods. They were found to be soluble in all solvents. The following melting points were recorded; 202 o C, 320 o C, and 292 o C, for Fe (II) (sal) 2, Fe (II) (Nic) 2 and Fe (Sal/Nic) respectively. The rest are 162 o C, 316 o C and 196 o C for Co (Sal) 2, Co (Nic) 2 and Co (Sal/Nic) mixed ligand complex respectively. In the research work, it was found out that most of the complexes have high molar conductivity value, while some others have low molar conductivity value. The complexes with lower molar conductivity value are less soluble in solvents than the complexes with higher value. The FTIR spectra observed in all the complexes showed that the coordination of [Co (Nic) 2Cl2]and [Fe (Nic) 2 (H2O) 2] is between N of the amine group (NH2) and the metal of the complex. In [Co (Sal) 2 (H2O) 2] and [Fe (Sal) 2 (H2O) 2] complex; coordination occurred between O of C=O group and the metal M of the complex. And in [Fe (Sal/Nic) (H2O) 2] and [Co (Sal/Nic) (H2O) 2] mixed ligand complex, the coordination of the complex is between O of the salicylic acid, the metal M and N of the pyridine in nicotinamide. But in [Co (Sal/Nic) (H2O) 2] coordination occurred between the N of the amine group and the O from C=O of the carboxylic group in salicylic acid.