Degree Name

MS (Master of Science)

Program

Chemistry

Date of Award

12-2004

Committee Chair or Co-Chairs

Jeffrey G. Wardeska

Committee Members

Scott J. Kirkby, Thomas T.-S. Huang

Abstract

Spectroscopic studies have been used to describe the mechanism of the decomposition of hydrogen peroxide by solutions of a dimeric Cu(II) complex of a dissymetric Schiff base, [CuSALAD]2.H2O, and imidazole or methyl substituted imidazoles, B, which form monomeric CuSALAD.B2 complexes, in aqueous ethanol solvent. Freezing point depression and vapor pressure lowering studies were carried out to confirm the dimeric nature of the [CuSALAD]2.H2O complex that had been previously reported. The stoichiometry of the [CuSALAD]2.H2O-imidazole equilibrium was extensively studied pointing to a 1:4 stoichiometry. The CuSALAD.B2 adducts exhibited certain catalytic properties that mimic those of catalase enzymes. The different imidazoles were buffered to acidic, neutral and basic pH media in order to investigate the pH effects of this reaction. Two charge transfer (CT) bands were observed near 420 and 450 nm upon addition of hydrogen peroxide to CuSALADB2 solutions, and were associated with two proposed intermediates (CuBOOH and CuBOOCu). A mechanism consistent with these results has been developed. First order dependence of the rate on CuSALAD.B2 was observed in the presence of excess CuSALAD.B2 over hydrogen peroxide, whereas second order dependence was observed with the latter in excess. The CuBOOCu intermediate was unstable in the presence of EDTA, and a first order dependence of rate of formation of intermediate on both CuSALAD.B2, and hydrogen peroxide was observed.

Document Type

Thesis - Open Access

Copyright

Copyright by the authors.

Included in

Chemistry Commons

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