Concern over the role of chlorofluorocarbons (CFC's) in stratospheric ozone depletion'has led to an intense search for environmentally safe alternatives. One class of potential replacements is the hydrofluorocarbon (HFC) compounds. Unlike CFC's, which have atmospheric lifetimes on the order of 100 years, HFC's react relatively rapidly with OH radicals2 to form alkyl radicals which are then rapidly converted to the corresponding ...