Structure and magnetism of mono-, di-, and trinuclear benzoato cobalt(II) complexes

• Published in: Polyhedron 2011-04, Vol.30 (7), p.1367-1373
• Main Authors: Hudák, J., Boča, R., Dlháň, Ľ., Kožíšek, J., Moncoľ, J.
• Format: Article
• Language: English
• Subjects: Benzoato ligand; Co(II) complexes; Magnetism; Structure; Zero-field splitting
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2011.02.047

Mononuclear, dinuclear, and trinuclear cobalt(II) complexes containing benzoato ligands have been prepared and structurally characterized. The magnetic data confirm a considerable magnetic anisotropy due to the single-ion zero-field splitting term D. [Display omitted] ► The mononuclear Co(II) complex refers to a square bipyramid. ► The dinuclear complex possesses pentacoordinate Co(II) centers linked by the benzoato ligands. ► The trinuclear complex is a linear assembly of Co(II) centers held by the benzoato ligands. ► The electronic spectra of mononuclear and trinuclear complexes match the octahedral pattern. ► Magnetic susceptibility and magnetization data show large zero-field splitting. Three cobalt(II) – benzoato ( bz) complexes have been prepared and structurally characterized. In the mononuclear complex trans-[Co( bz) 2(H 2O) 2( nca) 2] the benzoato ligand is unidentate ( nca = nicotinamide). The dinuclear complex [(μ 2- bz) 4{Co( qu)} 2] is a structural analog of the copper acetate ( qu = quinoline) where four bidentate benzoato ligands link two cobalt(II) pentacoordinate centers. The trinuclear complex of the composition [Co 3( bz) 6( inca) 6] contains a central hexacoordinate {( bz) 2Co( inca) 2( bz) 2} unit in which the bidentate benzoato ligands held the central and peripheral cobalt(II) centers ( inca = iso-nicotinamide); the peripheral hexacoordinate {( bz)Co( inca) 2