Cationic and Anionic Fragmentation of Dichloromethane following Inner-Shell (Cl 1s) Photoexcitation

The cationic and anionic fragmentation of dichloromethane (CH 2 Cl 2 ) molecule have been investigated in the energy range of the Cl K shell by using synchrotron radiation, ion yield spectroscopy, and electron-ion coincidence spectroscopy. Total and partial ion-yield and mass spectra have been recorded as a function of the photon energy. We were able to identify several singly and multiply charged cationic fragments and the following anionic species: H - ; C - ; Cl - . The present results provide the first experimental report of negative ion formation from a molecule excited at the Cl Is edge. In addition, our electron-ion coincidence data provide strong evidence of the preservation of molecular alignment for the photodissociation of CH 2 Cl 2 after deep core-electron resonant excitation.