Metastable ion decomposition and collisional activation mass spectra of 1,2,3‐triarylpropen‐1‐ones

Substituents have been found to have a marked influence on the metastable ion decompositions and collisionally activated (CA) fragmentations of the M + ˙ ion of a number of 1,2,3‐triarylpropen‐1‐ones. An attempt has been made to confirm the structures of the rearrangement ions, [C 14 H 10 ] + ˙, [C 13 H 11 ] + ˙, [C 13 H 9 ] + and [C 12 H 8 ] + ˙ by comparison of their CA spectra with those of the corresponding ions produced from reference compounds. The results imply that [C 14 H 10 ] + ˙ and the M + ˙ ions of phenanthrene and diphenylacetylene have a common structure, [C 13 H 9 ] + and the fluorenyl cation have a common structure and [C 12 H 8 ] + ˙ and biphenylene molecular ion have a common structure. The available data indicate that the ion at m / z 167 consists of a mixture of structures, likely possibilities being diphenylmethyl, phenyltropylium and dihydrofluorenyl cations.