Green synthesis, characterization, and DFT calculations of diorganotin (IV) complexes of Schiff bases

GRAPHICAL ABSTRACT

ABSTRACT

Diorganotin (IV) complexes (1, 2, 3, 4), of the general formula R₂Sn(L)_m have been synthesized where R = n-But, n-Oct; m = 2 when L1 = N-[(Z)-(2-hydroxy-3-methoxybenzylidene)pyrazine-2-carboxamide and m = 1 when L2 = [3,4-bis-{[(E)-(2-hydroxy-3-methoxyphenyl) methylidene]amino}phenyl](phenyl)meth-anone. The prepared Schiff bases and diorganotin complexes have been characterized by elemental analysis, FTIR, and NMR (¹H, ¹³C, and ¹¹⁹Sn) spectroscopic studies. The molecular geometry, thermochemical values, and vibrational frequencies of two complexes in the ground state were calculated using the B3LYP density functional method with LANL2DZ basis set for Sn using Gaussian 09 software. A good correlation of theoretical and experimental results shows that in both the complexes the geometry around the central tin atom is tetrahedral. The studies were further extended to test and compare the in vitro cytotoxic activity of ligands and complexes against MCF-7 cell line by MTT assay. The IC50 values show that cytotoxic activity of ligands increased on complexation with tin metal.

KEYWORDS:

• Diorganotin
• Schiff base
• DFT
• MTT

Acknowledgments

The authors gratefully acknowledge the Head, Applied Sciences Department, PEC University of Technology, Chandigarh (India) for providing laboratory facilities and Head, Department of Chemistry, Panjab University, Chandigarh (India) for providing instrumental facilities for product analysis. The MTT assay performed at Deshpande Laboratories, an ISO certified organization, is also acknowledged.