Abstrakt

Synthesis, Spectroscopic Characterization and Antibacterial Properties of some Metal (II) Complexes of 2-(6-methoxybenzothiazol-2- ylimino)methyl)-4-nitrophenol.

Aderoju A Osowole, Anthony C Ekennia, and Benedict O Achugbu

Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Pd(II) complexes of the Schiff base 2-(6-methoxybenzothiazol-2-ylimino)methyl)-4-nitrophenol (HL) derived from condensation of 2-hydroxy-5-nitrobenzaldehyde and 2-amino-6-methoxybenzothiazole have been synthesized and characterized by percentage metal, solubility, infrared and electronic spectra measurements. Their in-vitro anti-bacterial activities against Bacillus subtilis, Staphylococcus aureus, Proteus mirabilis, Klebsiella oxytoca, Pseudomonas aeruginosa, and Escherichia coli were also evaluated. The metal complexes formed as [ML(NO3)].bH2O, where M = Mn, Co, Cu, Zn; b = 0.5 - 4, with the exceptions of the Pd(II) and Ni(II) complexes that analyzed as [Pd(L)2 ].4H2O and [Ni(L)Cl(H2O) ]. The infrared spectra confirmed that coordination by the Schiff base is via the imine nitrogen and phenol oxygen atoms respectively, resulting in a NO chromophores around the metal ion. The electronic spectra measurement was corroborative of a 4-coordinate tetrahedral/square planar geometry for the complexes. The complexes mostly exhibit good in-vitro antibacterial activities against S. aureus, E. coli and P. mirablilis with inhibitory zones range of 16.0-27.0 mm, 13.0-15.0 mm and 17.0-20.0 mm respectively. Its noteworthy that the Pd(II) and Zn(II) complexes had broad spectrum anti-bacteria activity against the bacteria used with the exception of B. subtilis with inhibitory zones range of 13.0-22.0 and 13.0-27.0 mm respectively.