title: Immobilization of cobalt(III) Schiff base complexes onto Montmorillonite-K10: Synthesis, experimental and theoretical structural determination.
abstract: The [Co(naphophen)(PPh3)(OH2)]ClO4 and [Co(naphophen)(PBu3)(OH2)]BF4 (where naphophen=bis(naphthaldehyde)1,2-phenylenediimine) complexes were synthesized and chracterized by FT-IR, UV-Vis, (1)H NMR, (13)C NMR spectroscopy and elemental analysis techniques. The coordination geometry of the synthesized complexes were determined by X-ray crystallography. Cobalt (III) complexes have six-coordinated pseudo-octahedral geometry in which the O(1), O(2), N(1) and N(2) atoms of the Schiff base forms the equatorial plane. These complexes showed a dimeric structure via hydrogen bonding between the phenolate oxygen and the hydrogens of the coordinated H2O molecule. The theoretical calculations were also performed to optimize the structure of the complexes in the gas phase to confirm the structures proposed by X-ray crystallography. In addition, UV-Visible and IR spectra of complexes were calculated and compared with the corresponding experimental spectra to complete the experimental structural identification. The synthesized complexes were incorporated onto the Montmorillonite-K10 nanoclay via simple ion-exchange reaction. The structure and morphology of the obtained nanohybrids were identified by FT-IR, XRD, TGA/DTA, SEM and TEM techniques. Based on the XRD results of the new nanohybrid materials, the Schiff base complexes were intercalated in the interlayer spaces of clay. SEM and TEM micrographs of the clay/complex shows that the resulting hybrid nanomaterials has layer structures.
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address: akianfar@cc.iut.ac.ir.
authors.forename: Ali Hossein
authors.initials: AH
authors.lastname: Kianfar
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia,11800 Minden, Penang, Malaysia.
authors.forename: Wan Ahmad
authors.initials: WA
authors.lastname: Kamil Mahmood
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Dinari
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Farrokhpour
authors.affiliation: Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Enteshari
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia,11800 Minden, Penang, Malaysia.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Azarian
keywords: Cobalt Schiff base complexes; DFT calculation; Insertion compounds; Modified clay; Montmorillonite-K10; X-ray crystallography