Description
| Abstract: | The electron-transfer and oxidation-reduction chemistry for the alkyl-iron and alkyl-cobalt porphyrins [(Por)M-R] and copper complexes has been investigated on the basis of cyclic voltammetric and controlled-potential-electrolysis measurements. Half-wave potentials for the oxidation and the reduction of (Por)M-R are directly influenced by the nature of the electron-donating or electron-withdrawing groups on the porphyrin ring and the structure of the alkyl groups. The redox potentials for a series of copper complexes are affected by the electron donating ability and the chelate effect of the ligands. Hydrolysis of the copper(EI) cations (Cu(II)Ln[^2+]) occurs in water. The reactivity of copper(I) complexes with dioxygen is directly related to the oxidation potential of the complexes in the solvent. The combination of Cu(II)(bpy)2 + and tertiary-butyl hydroperoxide induces O2 activation to oxygenate methylenic carbon to ketones. Mechanistic schemes have been developed on the basis of electrochemical and spectrophotometric characterizations and reaction-product profiles for copper(II)-bis(bipyridine) [Cu(II)(bpy)2[^2+]]/base-induced activation of O2 to dehydrogenate primary alcohols to aldehydes. The free energies of bond formation (-ΔG[BF]) for the (Por)M-R and copper-ligand (oxygen or nitrogen) bonds have been determined from the redox potentials fo the corresponding electrode reactions. The values of -ΔG[BF] are 14-35 kcal mol^-1 for iron porphyrins and 20-38 kcal mol^-1 for cobalt porphyrins which depend on the structures of the porphyrins and the alkyl groups. Apparent bond energies are 18-51 kcal mol^-1 for the Cu(II)-L bonds and 46-78 kcal mol^-1 for the Cu(I)-L bonds. The free energies of bond formation for the L[n]Cu(I)-OO bonds are 7-16 kcal mol^-1. |
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| Item Description: | Vita.
"Major subject: Chemistry." |
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| Physical Description: | xiv, 96 leaves : illustrations ; 28 cm |
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| Bibliography: | Includes bibliographical references. |
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