Dissociative electron attachment to 3-benzelidenephthalide and phenolphthalein molecules.

Electron attachment to the 3-benzelidenephthalide and phenolphthalein molecules and decay channels of their molecular anions were investigated by means of Dissociative Electron Attachment (DEA) spectroscopy and Electron Transmission Spectroscopy (ETS). Interpretations of these experimental data were supported with UV-spectroscopy and DFT calculations. The average electron detachment times for the long-lived molecular anions of 3-benzelidenephthalide and phenolphthalein were measured to be 150 microseconds at 120 °C and 560 microseconds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, oppositely 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.