ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A Novel Route for the Preparation of Hydrotalcite and Synthesis of Intercalated Reversible Dioxygen-Carrying Cobalt (II) Complexes

M. Zikmund, K. Putyera, and K. Hrnčiarová

Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-842 36 Bratislava

Abstract: Reacting a solid MgCO₃ . 3H₂O or Mg₅(CO₃)₄(OH)₂ . 5H₂O (nesquehonite, hydromagnesite, dypingite) with an aqueous solution of sodium aluminate and sodium hydroxide is a novel procedure to synthesize solid solutions with desired stoichiometric Mg/Al ratios in the hydrotalcite series [Mg_3-zAl(OH)_8-2x]₂[(CO₃)(H₂O)_4-x] (0 ≤ x ≤ 1).By mixing of an intermediate solid solution of magnesium aluminium oxide obtained by thermal decomposition of hydrotalcite with an aqueous solution of mono- or α,ω -dicarboxylates which contain N-donor atom in the presence of ethylene glycol as a swelling agent pillared aminocarboxylate derivatives of hydrotalcite are produced. Nitrogen donor atoms of aminocarboxylate pillars may react with cobalt(II) complexes to form coordinatively unsaturated cobalt(II) chelates. The synthesized model Co(salen) and Co(salophen) complexes immobilized in the interlayer region of anionic clays reversibly bind dioxygen and enjoy high stability in the course of oxygenation-deoxygenation cycles.

Full paper in Portable Document Format: 505a262.pdf

Chemical Papers 50 (5) 262–270 (1996)