I. The Catalytic Oxidation of Olefins by a Cobalt Complex. Ii. The Thermodynamics of Base Binding to a Cobalt Complex (Cosmdpt)

Oxidations are key steps in the industrial synthesis of most compounds made. Therefore understanding the mechanisms by which these types of reactions occur is important not only synthetically but also commercially. In many cases transition metal catalysts are used to improve the rate and/or selectivity of such oxidations. Many homogeneous oxidations catalyzed by transition metal complexes, especially those containing first row transition metals, proceed by autoxidation. Since this is a free radical chain reaction the reaction generally is not selective and a variety of products are formed. In chapter I of this thesis is reported a mechanistic study of the oxidation of olefins by cobalt bis(salicylidene-(gamma)-iminopropyl)methylamine, abbreviated CoSMDPT, to selectively form ketones and alcohols. This product selectivity and other studies indicate that common autoxidation is not occurring in this system. A Wacker-type pathway (using water) and the involvement of peracids were also ruled out. Instead a mechanism is proposed which involves the formation of a cobalt hydroperoxide from CoSMDPT and hydrogen peroxide formed in situ by oxidation of the alcohol solvent. Addition of the cobalt hydroperoxide across the olefin double bond leads to an alkyl hydroperoxide which is subsequently decomposed by the Haber-Weiss mechanism to yield the ketone and alcohol products. Deactivation of the catalyst occurs during the reaction due to oxidation of the SMDPT ligand as well as formation of a (mu)-peroxocobalt dimer.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Hamilton, Dorothy Ellen

• Chemistry, Inorganic

Identifier

(UMI)AAI8511614

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70290