Abstract: The fragmentations of three bifunctional phenylether compounds including 2-(2,6-dichlolo)phenoxyl propionitrile, N-hydroxyl-4-butoxyl phenylacetyl amine (bufexamc) and 2-(1-methylethoxyl) phenol methylcarbamate (Propoxur) under electron impact ionization were reported.Metastable ion(MI) and collision-induced dissociation(CID) at a low energyhave been used to study the fragmentation pathways from molecular ions.Apart from the simple bond cleavages, and the unimolecular dissociations viaion/neutral complex intermediate as a competitive mechanism were demonstrated-Moreover, the intramolecular hydrogen transfer and double hydrogen transfers in the fragmentations of these compounds were discussed in detail.

Key words: Ion/neutral complexes, 2-(2,6-Dichloro) phenoxyl propionitrile, N-hydroxyl-4-butoxyl phenylacetylamine, 2-(1-Methylethoxyl) phenol methylcarbamate, Fragmentation of mass spectra