title: Co(iii) complexes of (1,3-selenazol-2-yl)hydrazones and their sulphur analogues.
abstract: The first Co(iii) complexes with (1,3-selenazol-2-yl)hydrazones as an unexplored class of ligands were prepared and characterized by NMR spectroscopy and X-ray diffraction analysis. The novel ligands act as NNN tridentate chelators forming octahedral Co(iii) complexes. The impact of structural changes on ligands' periphery as well as that of isosteric replacement of sulphur with selenium on the electrochemical and electronic absorption features of complexes are explored. To support the experimental data, density functional theory (DFT) calculations were also conducted. Theoretical NMR chemical shifts, the relative energies and natural bond orbital (NBO) analysis are calculated within the DFT approach, while the singlet excited state energies and HOMO-LUMO energy gap were calculated with time-dependent density functional theory (TD-DFT). The electrophilic f-and nucleophilic f+Fukui functions are well adapted to find the electrophile and nucleophile centres in the molecules. Both (1,3-selenazol-2-yl)- and (1,3-thiazol-2-yl)hydrazone Co(iii) complexes showed potent antimicrobial and antioxidant activity. A significant difference among them was a smaller cytotoxicity of selenium compounds.
authors.affiliation: Department of Chemistry and Biochemistry, Faculty of Agriculture, University of Belgrade, Nemanjina 6, Belgrade, Serbia.
authors.forename: Nenad R
authors.initials: NR
authors.lastname: Filipović
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade, Serbia.
authors.forename: Hana
authors.initials: H
authors.lastname: Elshaflu
authors.affiliation: Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, Belgrade, Serbia.
authors.forename: Sonja
authors.initials: S
authors.lastname: Grubišić
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 4, Novi Sad, Serbia.
authors.forename: Ljiljana S
authors.initials: LS
authors.lastname: Jovanović
authors.affiliation: Department of Chemistry, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 4, Novi Sad, Serbia.
authors.forename: Marko
authors.identifier: http://orcid.org/0000-0002-4471-8001
authors.initials: M
authors.lastname: Rodić
authors.affiliation: Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, Belgrade, Serbia.
authors.forename: Irena
authors.initials: I
authors.lastname: Novaković
authors.affiliation: Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia. tamarat@chem.bg.ac.rs.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Malešević
authors.affiliation: Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, Belgrade, Serbia.
authors.forename: Ivana S
authors.initials: IS
authors.lastname: Djordjević
authors.affiliation: University of Bordeaux, Bordeaux INP, ENSCBP, Institut des Sciences Moléculaires, CNRS UMR 5255, 16 Avenue Pey-Berland, 33607 Pessac, France.
authors.forename: Haidong
authors.initials: H
authors.lastname: Li
authors.affiliation: University of Bordeaux, Bordeaux INP, ENSCBP, Institut des Sciences Moléculaires, CNRS UMR 5255, 16 Avenue Pey-Berland, 33607 Pessac, France.
authors.forename: Nešo
authors.initials: N
authors.lastname: Šojić
authors.affiliation: Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade, Serbia.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Marinković
authors.affiliation: Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia. tamarat@chem.bg.ac.rs.
authors.forename: Tamara R
authors.identifier: http://orcid.org/0000-0002-7740-3639
authors.initials: TR
authors.lastname: Todorović