Mn(III), Zn(II) and Pt(II) macroacyclic complexes: Synthesis, X-ray structures, anticancer and antioxidant activities

The preparation of Manganese(III), Zinc(II) and Platinum(II) macroacyclic complexes drived from a previously known Schiff base ligand (H2L) and corresponding metal ions is described. While manganese and zinc formed complexes with the ligand, the reaction of K2PtCl4 resulted in hydrolysis of the ligand and the formation of the Pt(II) complex with the polyamine, 2,2′-(piperazine-1,4-diylbis(methylene))dianiline (L′). The three new complexes were characterized by elemental analysis, mass spectrometry, molar conductivity, FT-IR, 1H NMR and 13C NMR. The single crystal X-ray structural analysis of the [MnL]+ cation showed that the manganese has been oxidized to Mn(III) which is in a slightly distorted trans-O2N4 octahedral coordination environment arising from all six donor atoms of the doubly deprotonated ligand. The conformation of the [PtL′]2+ cations in both crystal forms of the complex is similar, with the platinum being in a square planar environment coordinated by the four nitrogen atoms of the 2,2′-(piperazine-1,4-diylbis(methylene))dianiline ligand (L′). We have also evaluated the anticancer activity of the synthesized compounds against human gastric (AGS, IBRC C 10071) and lung (A549; IBRC C10080) cell lines. Furthermore, the antioxidant potency of all compounds has been surveyed. © 2020 Elsevier B.V.