Executive Summary : | This project aims to isolate non-coordinated and coordinated reactive organic radicals, which are useful in the pharmaceutical industry. The project will use single crystal X-ray crystallography, Variable temperature EPR spectroscopy, and Density Functional Theory (DFT) calculations to authenticate the molecular and electronic structures of these radicals. The project will also explore redox cascade reactions of redox active chelates, which provide functional organic derivatives. The electron transfer potential of these chelates is significantly dependent on the metal ion, and their reactions and products will be examined with different 3d and 4d metal ions. Proton coupled redox reactions will be investigated, examining the shift of potential from the stepwise electron transfer-proton transfer path to the proton coupled redox path of redox active chelates. Radical coupling reactions and biphenyl derivatives will be controlled by changing the reaction medium, metal ion, and co-ligand to achieve desired derivatives. Metal ligand electron transfers will be analyzed, revealing that the electron localization on the ligand differs significantly from that on the metal ion of a redox active chelate. The switching potential of these ligands and their reactions with O2 and O2- will be analyzed. Redox active chelates play a significant role in activating dioxygen molecules, even with a redox inactive metal ion. They can afford the superoxide intermediate, [(L0)Mn++O2→[ (L1+)Mn+-(OO).-], expanding the activity of metal ions. Lastly, the project will model catalysts, focusing on two electron redox processes of a metal ion, involving oxidative addition and reductive elimination reactions. |