N,N'-Bis(furaldehyde)-1,2-phenylenediamine cobalt(II) chloride (1), N,N'-bis(furaldehyde)-ethylenediamine cobalt(II) chloride (2), N,N'- bis(furaldehyde)-1,2-diaminopropane cobalt(II) chloride (3), N,N'-bis (furaldehyde)-1,3-diaminopropane cobalt(II) chloride (4) were prepared and characterized by IR, ~1H NMR and elemental analysis. The stoichiometries of dioxygen uptake by these complexes at different temperature in pyridine solution were determined. Their oxygenation equilibrium constants and thermodynamic data ΔH°, ΔS° were calculated. The catalytic activities and selectivities of the cobalt complexes in cyclohexene oxidation were examined. The influences of temperature and ligand structure on dioxygen affinity of the complexes were discussed. The order of catalytic activities of the cobalt complexes with different ligand is 1 > 4 > 3 > 2. The addition of N- hydroxyphthalimide (NHPI) significantly increases the rate of the catalytic oxidation and the selectivities for 2-cyclohexene-1-one formation.

Key words: SCHIFF BASE, COBALT COMPLEX, OXIDATION, CATALYTIC REACTION, CYCLOHEXENE, BENZENEACETAMIDE P