Generation and fragmentation of phthalide derivative negative ions

Molecules of diphenylphthalide and 3,3-diphenylphthalide-4',4'-dicarbonic acid have been studied using the method of dissociative electron capture negative ion mass spectrometry. The mean lifetimes of negative molecular ions relative to the electron detachment have been measured. The electron affinity has been estimated in the Arrhenius approximation and calculated by the DFT B3LYP/6-31G+(d) method.