The obtained IC50 value of the DPPH activity for the L1-Ni complex (1.155+-0.054 uM) and that of the metal chelating activity for the L2H ligand (% = 75+-5.624) were higher than the values obtained for the other compounds.
In this study, we reported the synthesis and characterization of Co(II), Ni(II) and Zn(II) complexes with (L1H and L2H).
To a solutions of (1.993 g, 0.008 mol) sulfapyridine dissolved in 100 ml absolute EtOH (1.608 gr, 0.008 mol) 5-bromosalicylaldehyde dissolved in 10 ml absolute EtOH (for L1H), (1.336 gr, 0.008 mol) 5-nitrosalicylaldehyde dissolved in 10 ml absolute EtOH (for L2H) were added dropwise at 78 AdegC with continuous stirring for 6h.
For L2H: (398.39 g/mol) was obtained in 89 % yield; IR (KBr, I, cm-1): 3435 (O-H), 1618 (C=N), 1458 (C-O), 1336 (O=S=O)asym, 1137 (O=S=O)sym; 1H-NMR (DMSO-d6, I', ppm): 13.40 (s, 1H, O-H), 11.68 (s, 1H, N-H), 9.11 (s, 1H, CH=N), 8.43-6.55 (m, 11H, Ar-H); 13C NMR (DMSO-d6, I', ppm): 166.40 (C7), 153.22 (C1), 152.77 (C8), 151.08 (C12), 146.85 (C16), 141.39 (C11), 139.96 (C4), 139.21 (C14), 131.21 (C3), 129.38 (C5), 128.50 (C10), 124.91 (C9), 119.62 (C6), 119.05 (C2), 118.60 (C15), 112.86 (C13); Elemental analyses (%): calculated C, 54.27; H, 3.54; N, 14.06; S, 8.05; found C, 55.94; H, 3.72; N, 14.37; S, 8.35; UV (DMF, I>>, nm): 370 (naI*), 290 (IaI*).