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Dinuclear Zn(II) and tetranuclear Co(II) complexes of a tetradentate N 2 O 2 Schiff base ligand: Synthesis, crystal structure, characterization, DFT studies, cytotoxicity evaluation, and catalytic activity toward benzyl alcohol oxidation
Author(s) -
Sanatkar Tahereh Hosseinzadeh,
Khorshidi Alireza,
Janczak Jan
Publication year - 2020
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.5493
Subject(s) - chemistry , ligand (biochemistry) , schiff base , square pyramidal molecular geometry , crystallography , crystal structure , octahedron , stereochemistry , infrared spectroscopy , single crystal , electron paramagnetic resonance , octahedral molecular geometry , magnetic susceptibility , nuclear magnetic resonance , organic chemistry , receptor , biochemistry , physics
Two novel dinuclear Zn(II) and tetranuclear Co(II) complexes of a tetradentate N 2 O 2 Schiff base ligand (H 2 L = N , N′ ‐bis‐(4‐hydroxysalicylidene)‐1,3‐diaminopropane) were prepared. The structures of the H 2 L ligand, [4(Zn 2 L (μ‐O 2 CCH 3 )(O 2 CCH 3 )(H 2 O))]⋅4CH 3 OH⋅3H 2 O (complex 1 ) and [Co 4 L 2 (μ‐O 2 CCH 3 ) 2 (O 2 CCH 3 ) 2 ]⋅2H 2 O (complex 2 ) were unambiguously characterized by elemental analysis, mass spectrometry, Fourier‐transform infrared spectroscopy (FT‐IR), 1 H nuclear magnetic resonance (NMR), and UV–Vis spectroscopy. Single crystal X‐ray diffraction studies revealed that two Zn(II) nuclei of 1 were connected through μ‐phenolato and μ‐acetato bridges and had distorted square pyramidal and distorted octahedral coordination geometries. Four Co(II) nuclei of 2 , on the contrary, showed a Co 4 O 4 cubane‐like configuration in which Co(II) cations and O atoms were located at alternating corners of a distorted cube. Density functional theory studies at the B3LYP/6–31 G(d) level were carried out to gain an insight into the thermodynamic stability of the complexes. in vitro cytotoxicity of the ligand and the complexes were evaluated using the MTT assay against breast cancer MCF7 cells, melanoma cancer A375 cells, and prostate cancer PC3 cells as representative human cancer cell lines. Complex 1 showed a remarkable activity against A375 and PC3 cancer cell lines. In addition, 1 and 2 were used as precursors to produce zinc and cobalt oxide nanoparticles via pyrolysis technique. The resulting ZnO and Co 3 O 4 nanoparticles were characterized using FT‐IR spectroscopy, UV–Vis diffuse reflectance spectroscopy, powder X‐ray diffraction, and field emission scanning electron microscopy. Then, these nanoparticles were used as heterogeneous catalysts in the oxidation of benzyl alcohol with hydrogen peroxide at room temperature. Both catalysts showed good recyclability with a negligible decrease in their efficiency during four catalytic cycles. The results of theoretical calculations showed that the most stable product was benzaldehyde, which is in good agreement with the obtained experimental results.