Mass spectra of some perfluoroalkyl and perfluoroalkylether substituted 1,3,4-oxadiazoles

Electron impact fragmentation patterns were obtained for 2,5-bis-(perfluoroalkyl)-, 2,5-bis(perfluoroalkylether)-, and 2-perfluoroalkylether-5-perfluoroalkyl-1,3,4-oxadiazoles. All compounds gave parent ions. Cleavage β to the oxadiazole ring occurred preferentially; however, cleavage α to the ring also took place. Fragmentation of the ring was accompanied by the loss of a fragment of mass 28; this was most evident in the case of 2,5-bis(perfluoro-n-heptyl)-1,3,4-oxadiazole.