Synthesis, spectral characterization of Co(II), Ni(II), Cu(II) and Zn(II) complexes of Schiff bases derived from 3-formyl quinoline and 2,6-diaminopyridine and their biological studies

A series of Schiff bases derived from 2-mercapto-3-formyl quinoline/2-hydroxy-3-formyl quinoline with 2,6- diaminopyridine (DAP) and their corresponding transition metal complexes were synthesized, characterized by elemental analysis, spectral (IR, 1H-NMR, Mass, UV-Vis, Fluorescence, ESR, TGA) and magnetic studies. The molar conductances in DMF solution indicated that the complexes were non-electrolytic. The Schiff bases and their metal complexes were screened for analgesic, anti-inflammatory and antipyretic activities. Among all the compounds, the copper complexes had the greatest pharmacological activities.