Dissociative electron attachment to 3-benzelidenephthalide and phenolphthalein molecules.

Abstract

Electron attachment to the 3-benzelidenephthalide and phenolphthalein molecules and decay channels of their molecular anions were investigated by means of dissociative electron attachment spectroscopy and electron transmission spectroscopy. Interpretations of these experimental data were supported with UV-spectroscopy and density functional theory calculations. The average electron detachment times for the long-lived molecular anions of 3-benzelidenephthalide and phenolphthalein were measured to be 150 µs at 120 °C and 560 µs at 190 °C, respectively. The long-lived molecular anions of phenolphthalein are ascribed to an isomer formed by ring opening. The present results suggest that, opposite to phenolphthalein, polymeric materials based on 3-benzylidenephthalide cannot be switched to a high conductive state due to different mechanisms of stabilization of their long-lived molecular anions.