Upon collisionally activated dissociation (CAD) phenoxide ion experiences fragmentation reactions in the gas phase that produce the daughter ions [C6H3]-, [C5H5]-, [C2HO]-, and [C3H3]-. Based upon study of the anions derived from 2,3,4,5,6-pentadeuteriophenol (2), 4-deuteriophenol (3), 3,5-dideuteriophenol (4), and 2,4,6-trideuteriophenol (5), mechanisms for formation of the [C6H3]-, [C5H5]-, and [C2HO]- ions have been proposed.