PHOTON-INDUCED ELECTRON-ATTACHMENT AND ELECTRON DETACHMENT CHEMISTRY OF P-BENZOQUINONE AND ITS METHYLATED DERIVATIVES

Two aspects of the simultaneous interaction of low-energy electrons an d light with p-benzoquinone (BQ) and three methyl-substituted BQs are characterized here using an atmospheric pressure ionization mass spect rometer (APIMS) and a photodetachment-modulated electron capture detec tor (PDM-ECD). An optically enhanced electron capture reaction by BQ i s shown to occur by a mechanism involving the photochemical production of the dimer, (BQ)(2), followed by electron capture by this species. Electron photodetachment cross sections of the benzoquinone negative i ons are also reported here for the first time and indicate that the st ructures of the parent neutrals and molecular anions are significantly different.