Two perhalo-1, 4-dioxins, representatives of a previously unknown class of compounds, have been synthesized and shown to exhibit unusual reactivity. In particular, reaction with oxygen is spontaneous and exothermic, and radical-catalyzed homopolymerization will proceed through a fluorinated double bond. Representatives of the perhale2, 3-dihydro-1, 4- dioxin class have also been prepared and found to have reactivity in general intermediate ...