A series of Cu(III)-OH complexes supported by differently substituted bis(carboxamido)pyridine ligands is modeled to identify factors affecting electronic structure and hydrogen atom transfer reactivity. Activation of hydrocarbon substrates is inferred to be influenced by a combination of many factors, including overall charge state, counterion nature (when present), solvation, attractive and repulsive steric interactions, and quantum mechanical tunneling along the reaction coordinate.