Mechanistic Studies of Oxygen Activation and Atom Transfer Reactions with Mononuclear Vanadium(III), Iron(II), and Palladium(0) Complexes

This thesis comprises the area of oxygen binding, activation, and related oxygen atom transfer processes promoted by mononuclear transition metal complexes of vanadium(III), iron(II), and palladium(0).;The first part of this thesis details the mechanistic studies of ligand binding and oxygen atom transfer (OAT) reactions to the three-coordinate complex VIII(N[tBu]Ar)3 (Ar = 3,5-Me2C6H3). The kinetics of OAT to V(N[tBu]Ar)3 from N2O and other N-oxides is presented in Chapter 1, which revealed a wide range of kinetic behavior influenced by the mode and strength of coordination of the N-oxide and its ease of atom transfer. The importance of ligand binding, the initial step in the OAT reaction, is highlighted. Chapter 2 presents the kinetics of nitrile (RCN) binding to V(N[tBu]Ar)3, which serves as a comparative study with Mo(N[tBu]Ar)3. Studies revealed much faster binding of nitriles to V(N[tBu]Ar)3, which coordinate exclusively in an &;Chapter 4 details the mechanistic study of dioxygen binding to Pd0(IPr)2 (IPr = 1,3-bis(2,6-diisopropyl)phenylimidazol-2-ylidene), which forms an unprecedented trans-(&;The comparative study of biomimetic non-heme iron complexes supported by aminopyridine macrocyclic ligands (PyMACs) is presented in Chapter 5, including the preparation of two novel complexes that are potent oxygenation catalysts. This work highlights the effect of the axial donor on the structure and reactivity towards olefin epoxidation and provides preliminary insight into the nature of reactive intermediates.