Structural and antimicrobial properties of 3-[-2-(1,5-dimethy 3-oxo-2-phenyl-2,3- dihydro-1H-pyrazol-4-yl) hydrazilidine]-1,3-diphenylpropane-1,3-dione and its Co(II), Fe(III), Cu(II) and Ni(II) complexes

This work aims at synthesizing new hydrazone molecules with enhanced antibacterial capabilities. Diazotized 4-aminoantipyrine and 1,3-diphenyl-1,3-dione were coupled at around 5 oC to yield 3-[-2-(I,5-dimethy-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl) hydrazilidine]1,3-dione-1,3-diphenylpropane (HPDP). Its Co(II), Fe(III), Cu(II), and Ni(II) complexes were formed by refluxing stoichiometric amounts of chloride salts in separately with HPDP for 6 hours at 60 oC. HPDP and its complexes were characterized by means of spectroscopic techniques, conductivity, micro elemental analysis and melting point. Only HPDP X-ray diffraction spectral was obtained. The in-vitro antibacterial tests of compounds were done on Bacillus subtilis, Streptococcus pneumoniae, Pseudomonas aeruginosa, Escherichia coli (Eco 6 and Eco 13), Staphylococcus aureus, Protus, Staphylococcus intermedius (G101), Klebsiella pneumoniae and Salmonella Typhi. Spectroscopic studies show that HPDP is terdentately coordinated to the metal ion to form octahedral complexes with the acetyl, hydrazinyl nitrogen, and pyrazolone ring carbonyl groups. HPDP crystallized as monochronic with space group PbCa and unit dimensions a = 9.5528(8) Å, α = 90o; b = 19.6260(16) Å, b = 101.426(6)o; c = 12.058(10) Å, g = 90o for z = 4. Antimicrobial evaluations show that HPDP and [Ni(PDP)2] exhibited antibacterial activity against Salmonella. Typhi and Staphylococcus aureus up to the least concentration (0.31 μg/cm3), suggesting their potential for application as antibacterial drugs. KEY WORDS: Selenium, Amino acids, Vitamin B3, Mixed ligand, Complexes, Antioxidant Bull. Chem. Soc. Ethiop. 2024, 38(6), 1691-1702. DOI: https://dx.doi.org/10.4314/bcse.v38i6.15