Template Synthesis and Biological Study of Ni (II) Complexes derived from ethylenediamine and 2,4-pentanedione

Abstract

In this study, nickel (II) complexes having formulae [Ni(en)2(acac)] and [Ni(acac)₂.2H₂O], have been synthesised from bis-ethylenediamine nickel (II) chloride, nickel bromide hexahydrate and 2,4-pentanedione as starting material. The complexes were characterised using various physicochemical analysis such as Infrared, electronic spectra, elemental analysis, molar conductivity, thermo gravimetric analysis (TGA) and high resolution mass spectroscopy (HRMS). The IR spectral data of the complexes indicates the possible bonding/coordination of the ligands with the metal ion through oxygen and nitrogen atoms of the carbonyl and amine respectively, given rise to octahedral geometry. The elemental analysis and HRMS data obtained also agreed with the proposed molecular formula of the complexes. The result of molar conductivity studies in methanol solution (10–3M) showed that the complexes are electrolytes, and they are also soluble in polar solvents which include: methanol, ethanol, DMF, DMSO and slightly soluble in distilled water. The complexes has been tested for biological activities (anti-microbial and anti-fungal) using disc diffusion method and poisoned food techniques for anti-microbial and anti-fungal, respectively against Gram-positive bacteria: Staphylococcus aureus-ATCC 25923, Streptococcus Pyogene-ATCC 19615, Bacillus Subtilis-ATCC 23857, Gram-negative bacteria: Escherichia Coli- ATCC 25922, Salmonella typhi-ATCC 6539, Klebsiella Pneumonioe-ATCC 13883, Pseudomonas aeruginosa- ATCC 27853 and fungus: Candida albicam-ATCC 10231, using different concentrations (30, 20 and 10 μgmL–1) of the complexes. The comparative study of antimicrobial and anti-fungal activities of complexes with standard drugs, streptomycin and Fluconazole indicated that the complexes exhibit less activity as compared to the standard drugs at all the concentrations tested.

Keywords: Antibiotics, Complexes, Microbial, Transition metals