Syntheses, X-ray structure and biological studies of binuclear μ-oxo diiron complexes with s-triazine pincer ligand

The new binuclear mu-oxo diiron complexes, [Fe2(PMT)2(H2O)4O]X2 (X = NO3 over line ; 1 or Br over line ; 2), were synthesized. The bis-pyrazol-methoxy-s-triazine (MBPT) ligand underwent O-demethylation in presence of Fe(NO3)3 affording 4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2(1H)-one (HPMT) followed by in situ complexation to give 1 in a good yield. Repeating the reaction in presence of KBr, complex 2 was obtained. The Fe(III) is hexa coordinated in both complexes with 1 PMT over line as an anionic tridentate N-chelator, two water molecules in addition to the oxo-bridge. Both complexes have promisinig anticancer activity against lung carcinoma with IC50 of 15.27 +/- 0.75 and 46.14 +/- 2.07 mu g/mL for complex 1 and 2, respectively compare to cis-platin (IC50 = 7.53 +/- 0.69 mu g/ mL) as control. Hence, complex 1 outer performed complex 2 by three times. The antioxidant activity of complex 2 (IC50 = 50.36 +/- 2.96 mu g/mL) is better than 1 (IC50 = 349.92 +/- 17.48 mu g/mL). Also, the studied Fe(III) complexes have weak to moderate activities compared to Ketoconazole and Gentamycin as antibacterial and antifungal controls.