title: Eight- and six-coordinated Mn(II) complexes of heteroaromatic alcohol and aldehyde: crystal structure, spectral, magnetic, thermal and antibacterial activity studies.
abstract: Crystal, molecular and electronic structure of new manganese(II) compounds: [Mn(2-CH2OHpy)2(NO3)2] (1), [Mn(4-CHO-5-MeIm)2(NO3)2] (2) and [Mn(4-CHO-5-MeIm)2Cl2] (3), where 2-hydroxymethylpyridine (2-CH2OHpy) and 5(4)-carbaldehyde-4(5)-methylimidazole (5(4)-CHO-4(5)-MeIm), have been characterised using X-ray, spectroscopic, magnetic and TG/DTG data. In compounds 1 and 2, the Mn(II) ion is eight-coordinated forming distorted pseudo-dodecahedron, that is rather unusual for the manganese(II) complexes, whereas in 3 the Mn(II) ion environment is a distorted octahedron. The high coordination number (CN=8) of 1 and 2 results from bidentate character of the nitrate ligands. The X-band EPR spectra of compounds 2 and 3 exhibit fine structure signals resulting from zero-field splitting (ZFS) of the spin states for high spin d(5) Mn(II), whereas for 1 the broad isotropic signals were observed. The estimation of ZFS for individual Mn(II) ions was carried out for all compounds using DFT calculations. The free ligands and their manganese(II) complexes have been tested in vitro against gram-positive and gram-negative bacteria in order to assess their antimicrobial properties.
authors.affiliation: Institute of Chemistry, Jan Kochanowski University in Kielce, 15G Świętokrzyska Str., 25-406 Kielce, Poland. Electronic address: agajw@yahoo.com.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Jabłońska-Wawrzycka
authors.affiliation: Institute of Chemistry, Jan Kochanowski University in Kielce, 15G Świętokrzyska Str., 25-406 Kielce, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Barszcz
authors.affiliation: Institute of Chemistry, Jan Kochanowski University in Kielce, 15G Świętokrzyska Str., 25-406 Kielce, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Zienkiewicz
authors.affiliation: Faculty of Chemistry, Jagiellonian University, 3 Ingardena Str., 30-060 Kraków, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Hodorowicz
authors.affiliation: Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie Str., 50-383 Wrocław, Poland.
authors.forename: Julia
authors.initials: J
authors.lastname: Jezierska
authors.affiliation: Faculty of Chemistry, Jagiellonian University, 3 Ingardena Str., 30-060 Kraków, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Stadnicka
authors.affiliation: Microbiology Department of Institute of Biology, Jan Kochanowski University in Kielce, 15 Świętokrzyska Str., 25-406 Kielce, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Lechowicz
authors.affiliation: Microbiology Department of Institute of Biology, Jan Kochanowski University in Kielce, 15 Świętokrzyska Str., 25-406 Kielce, Poland.
authors.forename: Wiesław
authors.initials: W
authors.lastname: Kaca
mesh_terms: D000438:Alcohols / Q000737:chemistry* / Q000494:pharmacology; D000447:Aldehydes / Q000737:chemistry* / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D008345:Manganese / Q000737:chemistry* / Q000494:pharmacology; D008958:Models, Molecular
chemical_list: D000438:Alcohols; D000447:Aldehydes; D000900:Anti-Bacterial Agents; D008345:Manganese
keywords: Antibacterial activity; Crystal structure; EPR spectroscopy; Magnetic properties; Manganese complex; N,O-donor ligand