These higher energy isomers, some of which are derived from the structural work of Foo and colleagues, are ranked in order of increasing formation enthalpy in Table . In a study of conventional ring strain energies in oxadiazetidines Benton and Magers showed that 1,2-oxazetidine is much less strained than all of the six systems examined in spite of the fact that its total electronic energy is some 121-16 kJ mol -1 higher than 1,3-oxazetidine. Galván and co-workers have shown that in contrast to 1,2-dioxetane, 1,2-oxazetidine cannot undergo chemiexcitation and subsequent chemiluminescence.