Synthesis, characterization, antibacterial, antifungal and anthelmintic activities of a new 5-​nitroisatin Schiff base and its metal complexes

The copper (II)​, cobalt (II)​, nickel (II) and zinc (II) complexes of 5 - nitroisatin Schiff base (L) (L = Schiff base derived from 5-​nitroisatin and 2-​methyl-​4-​nitroaniline) were synthesized and characterized. The authenticity of the ligand and its metal complexes has been established by micro anal., IR, NMR, LC​/MS, UV-​VIS and elec. conductance measurements. The ligand acts as a bidentate agent in which the carbonyl oxygen and the azomethine nitrogen of 5-​nitroisatin are involved in co-​ordination. Square planar geometry was proposed for the Cu (II) and Ni (II) complexes and tetrahedral geometry was proposed for the Co (II) and Zn (II) complexes. The ligand and its metal complexes have been screened for antibacterial activity against Staphylococcus aureus, Escherichia coli, etc. and for antifungal activity against Aspergillus niger, Aspergillus flavous, etc. The Schiff base and its complexes were also screened for anthelmintic activity on earthworms. Both samples displayed significant activitie