Polymeric oxidants in the bead form that were macroporous styrene/divinylbenzene copolymers containing N-chlorosulfonamide functional groups (in sodium or hydrogen form) or N-bromosulfonamide groups (in sodium form) were synthesized and investigated to determine their oxidizing powers. The redox potentials of the N-chlorosulfonamide/sulfonamide and N-bromo-sulfonamide/sulfonamide systems were determined by potentiometric studies at different pH values with aqueous solutions of Na2SO3, KCN, and KSCN as reducers. The formal redox potentials of the N-chlorosulfonamide copolymers were 0.79, 0.44, and -0.12 V at pH's of 1.8, 8.45, and 13.6, respectively. The formal redox potential of the N-bromosulfonamide copolymer was about 100 mV higher in comparable conditions and in solutions over pH = 5 (e.g., 0.56 V at pH = 8.56). The comparatively higher oxidizing power of the N-bromosulfonamide copolymer was particularly evident in a strong alkaline medium (in which the N-chlorosulfonamide copolymer was not reactive). In contrast, the N-chlorosulfonamide copolymer showed strong oxidative properties in acidic media (in which the N-bromosulfonamide copolymer decomposed itself). (c) 2007 Wiley Periodicals, Inc.