Thesis Format
Integrated Article
Degree
Master of Science
Program
Chemistry
Supervisor
Drover, Marcus W
Abstract
This thesis focuses on how incorporating a Lewis acidic secondary coordination sphere (SCS) into transition metal complexes can alter their reactivity in useful ways. In particular, boron in the SCS will be explored as the primary driving force behind imparting this differential reactivity in conjunction with transition metal compounds. The main feature of boron allowing it to influence reactivity in these complexes is its empty p-orbital and Lewis acidic nature when three-coordinate. There are several ways in which the synergy between a Lewis acidic borane and a transition metal complex are explored throughout this thesis. Chapter 1 introduces important concepts for each research project presented. Chapter 2 focuses on the synthesis of iridium diphosphine compounds with a Lewis acidic SCS, for applications in selective heteroarene borylation. Chapter 3 illustrates how pre-installation of a functional SCS into ligand frameworks can alter the type of complexes formed, as demonstrated by the synthesis of three iridium κ3-P,P,C compounds. Chapter 4 describes how the use of a Lewis acidic boron in the SCS of trisferrocenylborane allows for the creation of a tuneable redox flow battery (RFB) anolyte.
Summary for Lay Audience
Molecules of all kinds surround us in everyday life. Oxygen (O2) is in the air we breathe, sodium chloride (NaCl) is the salt in our food, and hydrocarbons (CXHY chains) are in the fuel we use. Most of these everyday chemicals are found naturally and can be purified for use by simple physical or chemical means. However, there are some molecules critical to society which cannot be produced without human chemical ingenuity. These compounds, including many pharmaceuticals, fertilizers, plastics, and electronic materials, often require a catalyst in order to be synthesized on the bulk scale or even at all. The first project of this thesis looks to synthesize a catalyst, which can be used to help access new types of compounds (or provide higher efficiencies when accessing known ones) that are especially relevant to the pharmaceutical industry. The goal was to develop a catalyst which is more selective for the product it makes, so that less time and money could be wasted on purification/synthesis. We aim to do this through utilizing unique properties of the element boron in conjunction with the transition metal iridium. Specifically, by incorporating boron into an iridium complex so that they are able to work together when reacting with molecules. In the second project of this thesis, we look into how pre-installing a boron or alkene group into a ligand (ligand = a molecule or atom which can bind to a metal) can alter reactivity and produce new and unexpected complexes. Importantly, we see pre-installing boranes or alkene groups can facilitate the synthesis of complexes with rare and underexplored ligand frameworks. This work creates new avenues for designing ligands which can react in specific ways with metal precursors, to obtain a complex with desirable properties. In the final project of this thesis, a molecule containing three metal compounds attached by a single boron is shown to be electrochemically tuneable. This is achieved through the binding other molecules with various properties to the central boron atom. This system is then subjected to electrochemical experiments to probe its potential for use in energy storage applications.
Recommended Citation
Demchuk, Mitchell J., "Investigating the Synergy Between a Lewis Acidic Secondary Coordination Sphere and Transition Metal Complexes" (2024). Electronic Thesis and Dissertation Repository. 10272.
https://ir.lib.uwo.ca/etd/10272
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