Density functional theory for the investigation of transition metal complexes: Structure, binding, and spectroscopy of metal-siderophores and the catalase-peroxidase enzyme

Since the development of quantum mechanics in the 1920's and with the introduction of the Schrodinger equation in 1926, various methods to solve the Schrodinger equation have evolved. With advances in these computational methods, we are now able to solve the Schrodinger equation for systems that did not seem possible less than a century ago. Density functional theory (DFT) is a valuable tool for the exploration of the molecular properties of biological systems, and is based upon the theory that the exact energy could be determined from the knowledge of the electron density. The purpose of this dissertation is to explore the use of modern density functional theory methods to compute the structural, spectroscopic and mechanistic properties of biological molecules. In particular, DFT will be use to explore insights into metal-ligand interactions of siderophore-transition metal complexes and to explore the properties of a unique tyrosyl-like radical of the Catalase Peroxidase (KatG) enzyme.