SYNTHESIS, SPECTRAL CHARACTERIZATION AND ANTIMICROBIAL STUDIES OF BIS(CYCLOPENTADIENYL)- ZIRCONIUM(IV) DERIVATIVES WITH QUINAZOLINONE SCHIFF BASES

Abstract

Zirconium(IV) complexes of types [(C5H5)2Zr(L)] and [(C5H5)Zr(LÂ’)Cl] (LH2 represents Schiff bases derived from quinazolinone and salycylaldehye or o-hydroxyacetophenone LÂ’H represents Schiff bases derived from quinazolinone and 4-fluorobenzaldehyde/ 4-fluoro acetophenone /1-(2-fluoro-4-methylphenyl)-2-methylpropan-1-one / 1-(2-fluoro-4-methylphenyl) propan-1-one ) have been synthesized by the reactions of bis(cyclopentadienyl)zirconium(IV) dichloride with appropriate ligands in tetrahydrofuran in the presence of triethylamine. All these complexes are soluble in THF, PhNO2, DMF and DMSO. The complexes were characterized by elemental analyses, electrical conductance, magnetic susceptibility, IR, 1H NMR, XRD and SEM spectral techniques. Low molar conductance values indicate non-electrolytic nature of the complexes. The spectral data indicate 5-coordinate geometry for the complexes. XRD pattern evince that the complexes have monoclinic crystal system and particle sizes were found in the range 46.40-49.30 nm (nano-size). In vitro antifungal activity of synthesized compounds was evaluated against fungi Aspergillus niger, Aspergillus fumigatus, Candida albicans and In vitro antibacterial activity was determined by screening the compounds against gram negative (P. aeruginosa, E.coli) and gram positive (S. aureus and B. subtilis) bacterial strains using minimum inhibition concentration method (MIC) by serial dilution technique. The zirconocene(IV) complexes have higher antimicrobial impact than the parent Schiff bases.