| Abstract: | The mass spectra of nitrophenylimidazoles and nitrophenylpyrazoles have been examined in order to establish whether neighbouring ortho-ortho′ substituents have an appreciable influence on the fragmentation patterns. For compounds having an ortho nitro group on the heterocycle, specific effects are observed. Isotope effects observed with deuterated derivatives confirm this and establish that in the case of o-nitroimidazoles the 2-H proton adjacent to both nitrogen atoms is involved in the loss of OH. Fragmentation of each compound is specific and study could eventually provide a satisfactory means for structure determination. |
