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

doi:10.1016/j.ica.2020.119705

Inorganica Chimica Acta

Volume 509, 1 September 2020, 119705

https://doi.org/10.1016/j.ica.2020.119705 Get rights and content

Highlights

•
The preparation of Manganese(III), Zinc(II) and Pt(II) macroacyclic complexes based on a previously known Schiff base ligand (H₂L).
•
Determination of structures of the [MnL]ClO₄∙0.58 CH₃OH, [PtL′]Cl_1.53I_0.47 and [PtL′]Cl_1.7I_0.3·0.73H₂O complexes by single-crystal X-ray structural analysis.
•
In vitro testing of the anticancer activity of the human AGS and A549 cancerous cell lines.

Abstract

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.

Graphical abstract

Introduction

Schiff-base complexes are the important stereochemical models for transition metal coordination chemistry because of their structural variety [1], [2]. The design of new multidentate ligands with nitrogen and oxygen donors and corresponding metal complexes are interesting filed due to their applications in biological systems and catalysis [3], [4], [5]. Piperazine, a six membered organic compound containing two opposing nitrogen atoms, is one of the most significant moieties in drug design. This moiety can be found in many well-known drugs with various therapeutic uses, such as antihistamine, antidepressant, antianginal, anti-inflammatory, antipsychotic, anticancer, cardio protectors, antiviral and imaging agents [6], [7], [8], [9], [10], [11], [12], [13], [14]. Recently we have synthesized a number of macrocyclic and macroacyclic Schiff base complexes containing the piperazine moiety and the biological properties of some of the complexes have been studied [15], [16], [17], [18], [19], [20]. As a continuation of this research, we now describe the synthesis, X-ray structure, anticancer and antioxidant activity of some macroacyclic complexes of Mn(III), Zn(II) and Pt(II) containing the piperazine moiety.

Section snippets

Materials

The ligand, 2,2′-(1Z,1′Z)-(2,2′-(piperazine-1,4-diylbis(methylene))bis(2,1-phenylene))bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)diphenol (H₂L) was synthesized according to the literature procedure [6]. Solvents and metal salts were purchased from the Merck Company.

Caution! Perchlorate salts are potentially explosive. Only small amounts should be used and handled with great care.

Physical measurements

Infrared spectra were recorded using KBr pellets on a Pekin-Elmer Spectrum 65 spectrophotometer (4000–400 cm⁻¹

Results and discussion

The macroacyclic Schiff base complexes (1) and (2) were obtained by reaction of the schiff base ligand H₂L with M(ClO₄)₂·6H₂O (M = Mn, Zn) in a methanol:ethanol solvent mixture while the macroacyclic complex (3) was prepared from the reaction of the schiff base ligand H₂L with K₂PtCl₄ in a DMSO:water solvent mixture; during the reaction hydrolysis of the ligand (H₂L) occurred. The products have been characterized by FT-IR, elemental analyses, mass spectrometry, ¹H and ¹³C NMR spectroscopy. The

Conclusion

The new macroacyclic Schiff base complexes (1) and (2) have been prepared from reaction of the schiff base ligand H₂L with M(ClO₄)₂·6H₂O (M = Mn, Zn) and macroacyclic complex (3) from reaction of the schiff base ligand H₂L with K₂PtCl₄. In the reaction of ligand H₂L and K₂PtCl₄ the Schiff-base ligand has hydrolyzed forming the Pt(II) complex with the polyamine 2,2′-(piperazine-1,4-diylbis(methylene))dianiline (L′). All of products were characterized by using a number of physical techniques. The

CRediT authorship contribution statement

Hassan Keypour: Supervision, Writing - original draft. Neda Ansari: Investigation. Masoumeh Mahmoudabadi: Writing - review & editing. Roya Karamian: . Seyed Hamed Moazzami Farida: . Mahboube Eslami Moghadam: Investigation. Robert William Gable: .

Declaration of Competing Interest

The authors declare that they have no known competing financialinterestsor personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgement

We are grateful to the Faculty of Chemistry of Bu-Ali Sina University, for financial support.

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

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Materials

Physical measurements

Results and discussion

Conclusion

CRediT authorship contribution statement

Declaration of Competing Interest

Acknowledgement

Coord. Chem. Rev.

Polyhedron

Polyhedron

Chem. Data Collec.

J. Med. Chem.

Coord. Chem. Rev.

J. Med. Chem.

Eur. J. Med. Chem.

J. Mol. Struct.

Polyhedron

Polyhedron

Polyhedron

Polyhedron

Inorg. Chim. Acta

Life Sci.

Phytomedicine

Chem. Rev.

Inorg. Chim. Acta

J. Organomet. Chem.

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