Abstract: | The metastable peak resulting from the fragmentation of [C7H7]2+? ions fram a variety of sources shows structure due to the presence of two reactions releasing different amounts of translational energy. The translational energy differences has been measured as 0.52 ± 0.04eV and is thought to be due to the formation of product ions of different structure via competing reactions from a single transition state. The possible structures of these ions are discussed, and it is proposed that the effect observed is due to the formation of [C3H3]+ ions in two forms, cyclopropenyl and proparg1. The metastable singly charged ions which also lead to product ions of formula [C3H, 3]+. |