Abstract: A series of transition metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Mn(II) and VO(II) have been prepared by tridentate Schiff base ligand containing N and O atoms. The Schiff base ligand(E)-1,5-dimethyl-4-(((4-oxo-4H-chromene-3-yl)methylene)amino)-2-phenyl-1H-pyrazol-3(2H)-one) have been synthesized by reaction between chromone-3-carboxaldehyde and 4-aminoantipyrineand characterized by Mass, 1H-NMR, FT-IR and UV-Visible spectroscopy and its metal complexes were characterised by FT-IR, UV-Visible, P-XRD, TGA and CHN analysis. All metal complexes exhibited 1:1 stoichiometry ratio of metal to ligand. The ligand and its metal complexes were screened for antibacterial, antifungal, anticancer and antioxidant activity. The biological activity of Schiff base ligand and its transition metal complexes has been studied by using four bacteria named as Staphylococcus aureus, Bacillus subtilis, Salmonella typhi and Klebsiella pneumonia and three fungi Penicillium chrysogenum, Trichoderma viride, Aspergillus niger by using disc diffusion method. The anticancer activity was screened by using MTT assay against human MCF-7 breast cancer cell line. The antioxidant activity was screened by using DPPH method. From all these observations it can be concluded that the Schiff base ligand and its transition metal complexes exhibited better activities.
Keywords: Schiff Base, chromone-3-carboxaldehyde, 4-aminoantipyrine, metal complexes, spectral and biological studies, etc.