SYNTHESIS AND CHARACTERIZATION OF MIXED LIGAND METAL (II) COMPLEX OF N,N-DIMETHYLIMIDODICARBONIMIDIC DIAMIDE, 2-HYDROXYBENZAMIDE AND 2-AMINO-6-HYDROXYPURINE

This study focuses on the synthesis and characterization of mixed ligands metal complexes of metformin, salicylamide, and 2-amino-6-hydroxypurine, with NiCl2.6H2O and CoCl2.6H2O. Upon coordination of the mixed ligands with metal(II) salt. The Ni(II) complex of the mixed ligand metformin and salicylamide produces a pink precipitate while the cobalt(II) complex of the mixed ligands metformin and 2-amino-6-hydroxypurine gives a deep blue precipitate. Solubility tests revealed that the ligands and their metal complexes were mostly insoluble in water and non-polar solvents with the Ni(II) complex of the mixed ligands. Spectroscopic analyses provided further structural insights. Infrared spectra displayed notable shifts in characteristic bands and the appearance of metal–oxygen and metal–nitrogen stretching vibrations, confirming successful coordination and establishing the ligands as bidentate donors through nitrogen and oxygen atoms (M-O=420-470 ) and (M-N=430-450 ). Ultraviolet–visible spectra of revealed d-d transition with absorption band at 722nm for nickel(II) complex and 510nm for the cobalt(II) complex supporting an octahedral geometry and distinct electronic environments. This findings confirm the successful synthesis, stability, and coordination behavior of the mixed-ligand metal(II) complexes. This work demonstrates how simple bioactive molecules such as metformin, salicylamide, and 2-amino-6-hydroxypurine can combine with transition metals to form complexes with valuable properties. These results open promising avenues for future applications in catalysis, medicinal chemistry, and material science while laying a solid foundation for continued exploration and innovation.