A nine-coordinated bismuth(III) Schiff-base complex: Design, synthesis, computational studies, and antimicrobial activity

A new bismuth(III) Schiff-base complex [Bi-2(HL)(2)(NO3)(4)] was synthesized by using equivalent molar of Schiff-base ligand [H2L = (E)-N '-(2-hydroxy-3-methoxybenzylidene)isonicotinohydrazide] and Bi(NO3)(3)center dot 5H(2)O with the assistance of Mannitol. The complex was structurally characterized by elemental analysis, spectroscopic methods, and single crystal X-ray diffraction. The experimental and theoretical vibrational bands (infrared and Raman spectra) have been discussed. The antimicrobial activity of the complex against Schizosaccharomyces pombe was evaluated by bio-microcalorimetry at 32 degrees C. Some thermokinetic parameters (k, P-max, t(G), and Q(total)) were obtained from the metabolic power-time curves of S. pombe, and their quantitative relationships with the concentration (c) were discussed. The half inhibition concentrations (IC50) of isoniazid, Schiff base, and the complex were calculated. The complex showed the strongest inhibition effect among three compounds.