title: Novel 1D chain Fe(III)-salen-like complexes involving anionic heterocyclic N-donor ligands. Synthesis, X-ray structure, magnetic, (57)Fe Mössbauer, and biological activity studies.
abstract: The iron(III) salen-type complexes [Fe(salen)(L)](n) (1-6) involving heterocyclic N-donor ligands HL {HL = 1H-imidazole (Himz), 1H-tetrazol-5-amine (Hatz), 5-methyl-1H-tetrazole (Hmtz), 1H-benzimidazole (Hbimz), 1H-1,2,4-triazole (Htriz) and 1H-benzotriazole (Hbtriz)} have been prepared and characterised by elemental analysis, FT IR, CI mass and (57)Fe Mössbauer spectroscopies, and variable temperature magnetic measurements. Single crystal X-ray analysis of [Fe(salen)(btriz)](n) (6) revealed a 1D chain-polymeric structure of the complex with the btriz anion as a bridging ligand. Magnetic data for all complexes were fitted using Fisher's model (for S = 5/2) and also using a heptanuclear closed ring model showing a weak antiferromagnetic interaction (J approximately -1 to -2 cm(-1)), and moreover, molecule-based magnet properties have been observed in the case of [Fe(salen)(atz)](n) (2). The exponential correlation between the magnetic properties (the isotropic exchange parameter J) and the basicity of the free ligands (K(b)) has been found. The antiferromagnetic ordering as well as a moderate structural dissimilarity in the vicinity of iron atoms has been proved by the (57)Fe Mössbauer low-temperature (2 K) in-field (7 T) experiments in the case of (2), in which two sextets with the line intensities (3/4/1/3/4/1) have been observed. The compounds have been tested for their SOD-like activity, DNA cleavage activity, and in vitro cytotoxicity against two human cancer cell lines: chronic myelogenous erythroleukemia (K562) and breast adenocarcinoma (MCF7). The best result regarding the cytotoxicity has been achieved for the complex of [Fe(salen)(atz)](n) (2), where IC(50) = 6.4 microM against K562.
authors.affiliation: Department of Inorganic Chemistry, Faculty of Science, Palacký University, Tr. 17. listopadu 12, CZ-77900, Olomouc, Czech Republic.
authors.forename: Radovan
authors.initials: R
authors.lastname: Herchel
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Sindelár
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Trávnícek
authors.forename: Radek
authors.initials: R
authors.lastname: Zboril
authors.forename: Ján
authors.initials: J
authors.lastname: Vanco
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D018360:Crystallography, X-Ray; D053837:DNA Cleavage; D005290:Ferric Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D007501:Iron / Q000737:chemistry*; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000378:metabolism; D008024:Ligands; D015204:Spectroscopy, Mossbauer; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D005290:Ferric Compounds; D008024:Ligands; D007501:Iron; D013482:Superoxide Dismutase