Synthesis and Characterization of Redox-Active Multidentate Ligands for Catalytic C-H Bond Oxidation and Carbon Dioxide Reduction

Author

Caroline HodgeFollow

Date of Award

Spring 4-25-2022

Document Type

Undergraduate Thesis

Department

Chemistry and Biochemistry

First Advisor

Jonah Jurss

Second Advisor

Jason Ritchie

Third Advisor

Walter Cleland

Relational Format

Dissertation/Thesis

Abstract

This thesis focuses on two research projects. The first project reported in Chapter 1 involves the synthesis and application of a tetradentate ligand (2-(1,1-di(pyridin-2-yl)ethyl)-1,10-phenanthroline, PhenPY2Me) that is metalated with iron to give a catalyst capable of carbon-hydrogen (C-H) bond oxidation. C-H bond oxidation provides a method that may allow some transformations in organic syntheses to be streamlined. The mononuclear iron complex supported by PhenPY2Me was found to dimerize in the presence of O₂ in a non-coordinating solvent. These iron complexes and a previously reported system were assessed and compared in C-H bond oxidation with model substrates using the sacrificial oxidant meta-chloroperbenzoic acid (mCPBA). It was found in cyclohexane oxidation that including scandium(III) triflate (Sc³⁺) as an additive to the reaction mixture increases the turnover number of the catalysts while selecting for the alcohol (cyclohexanol) over the ketone (cyclohexanone). The second project reported in Chapter 2 involves the synthesis of a pentadentate ligand (6-((1,4,7-triazonan-1-yl)methyl)-2,2'-bipyridine, BpyTacn) that will be applied to catalytic carbon dioxide reduction. The increased prevalence of greenhouse gases in the atmosphere has led to a greater need to develop catalysts capable of reducing carbon dioxide. Converting carbon dioxide into a more usable form would allow for net carbon emissions to be reduced. The use of a catalyst allows this process to occur in a more energetically favorably way. The synthesis of the ligand is discussed and preliminary cyclic voltammetry data with the corresponding cobalt complex shows a current enhancement in the presence of CO₂ that is indicative of catalytic activity.

Recommended Citation

Hodge, Caroline, "Synthesis and Characterization of Redox-Active Multidentate Ligands for Catalytic C-H Bond Oxidation and Carbon Dioxide Reduction" (2022). Honors Theses. 2593.
https://egrove.olemiss.edu/hon_thesis/2593

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