SYNTHESIS, SPECTROSCOPIC INVESTIGATION AND BIOEFFICACY OF SOME NOVEL SCHIFF BASE METAL (II) COMPLEXESAbstract
Two monobasic bidentate ligands L1H [2-(5-Bromo-2-dihydro-2-oxo-1H-indol-3-ylidene)hydrazine-carboxamide] and L2H [2-(5-Bromo-2-dihydro-2-oxo-1H-indol-3-ylidene)hydrazinecarbothioamide] were synthesized by the condensation of [2-(5-Bromo-2-dihydro-2-oxo-1H-indol-3-ylidene) with semicarbazide and thiosemcarbazide, which formed a series of complexes with cobalt(II) and nickel(II). The ligands and the metal complexes were characterized based on elemental analysis, IR, UV–Visible, 1HNMR, Mass spectroscopy. Spectral studies revealed that the ligands acted as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen i.e. >C=N and carbonyl oxygen atom of the isatin moiety. All the Schiff base metal complexes have a mononuclear structure, and the octahedral geometry has been proposed on the basis of spectral studies. The nickel (II) complex Ni (L2) (OAc).3H2O was subjected to XRD studies which revealed a monoclinic crystal system. In vitro, biological screening effects of the compounds were tested against two bacterial species Staphylococcus aureus and Escherichia coli. DNA cleavage and antioxidant activity of the ligands and their respective complexes were also examined.
Yogeshwari Satyawana, Naveen Sharma, Anita Kumari and Nighat Fahmi *
Department of Chemistry, University of Rajasthan, Jaipur, Rajasthan, India.
30 December 2020
06 April 2021
26 May 2021
01 November 2021