Unusual coordination of the superoxide ion O2− with molecules of halogenated hydrocarbons

EPR and NMR studies of solutions of KO 2 in halogenated hydrocarbons at 213-273 K have revealed paramagnetic centers differing form the superoxide ion 02-, the peroxy radical H02", and alkylhalogenoperoxy and alkylperoxy radicals RO='. These paramagnetic centers are probably molecular complexes of the superoxide ion 02with the molecules CHCI3, CH2C12, CH3CI , CHCI2F , CH=Br 2 and C~HCI 3. The complexes are formed by the two-center coordination of 02by interaction with a hydrogen atom (hydrogen bonding) and a halogen atom in the halogenated hydrocarbon.