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Updated: Jun 26, 2026
Effect of Microwave Synthesis Conditions on the Structure of Nickel Hydroxide Nanosheets
Published on: August 18, 2023
Can halogen atoms in coumarin derivatives affect the structure and antiproliferative activity of nickel(II)
Jakub Kurjan1, Erika Samolova2, Viktória Medvecová3
1Department of Inorganic Chemistry, Faculty of Science, Pavol Jozef Šafárik University in Košice, Moyzesova 11, 04154 Košice, Slovakia.
Abstract:
A multistep procedure from 4-halogeno-2-hydroxyacetophenones, proceeding through 7-halogeno-4-hydroxychromen-2-ones and 7-halogeno-3-acetyl-4-hydroxychromen-2-ones, followed by condensation with 2-picolylamine, was used to synthesize a new series of halogenated coumarin Schiff bases, namely, (3E)-7-halogeno-3-(1-{[(pyridin-2-yl)methyl]amino}ethylidene)-2H-1-benzopyran-2,4(3H)-diones [7-XHL, X (halogen) = F, Cl and Br; C17H13XN2O3]. The ligands 7-XHL and analogous (3E)-6-halogeno-3-(1-{[(pyridin-2-yl)methyl]amino}ethylidene)-2H-1-benzopyran-2,4(3H)-dione (6-XHL) derivatives were used to prepare nine new NiII complexes, divided in series: [Ni(L/6-ClL/7-FL/7-ClL)(NO3)], 1, 5, 7 and 8, [Ni2(L)2(H2O)4](NO3)2, 2, and [Ni2(6-XL/7-BrL)2(H2O)4](NO3)2, 3, 4, 6 and 9. All the complexes and ligands were characterized by IR spectroscopy and elemental analysis. Ligands 7-XHL were further characterized by NMR spectroscopy and single-crystal X-ray diffraction. Complexes 1-5, prepared in crystalline form, were also characterized by single-crystal X-ray diffraction. Detailed descriptions of the crystal structures in the solid state of the complexes and 7-XHL ligands are provided, including π-π interactions and unusual Ni...Ni interactions observed in all the complexes. All the complexes (except for 1 and 5) were screened for their in vitro antiproliferative activity against a panel of human cancer cell lines (MDA-MB-231, HCT-116, Jurkat, U87, A549, A2058, PaTu 8902 and HepG2), alongside a non-malignant colorectal cell line (CCD-18Co). The stability of these complexes in solution was proved by UV-Vis spectrophotometry for 72 h. Across the series, it was noted that introducing halogen substituents and varying their positions leads to a moderate increase in cytotoxicity compared with the non-halogenated parent ligand, and that complexes derived from 7-XHL are generally more active than their 6-XHL analogues.
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