Bond‐selective Photoion Correlations (“Memory Effects”) in Molecules from Site‐Specific 1s Excitation Using Synchrotron Radiation

Abstract

AbstractWe observe bond‐selective photoion‐photoion correlations in the molecules CF2 = CH2 and CF3–CH3 upon site‐specific C (1s) excitation at either the CF or the CH atom. The observed double photoion correlations can be interpreted as a chemical “memory effect” where the fragmentation process memorizes the initial site of energy deposition. A new “Zero Kinetic Energy Photoelectron”‐photoion‐photoion coincidence technique incorporating a high transmission mass spectrometer and a multi‐stop time‐to‐digital converter is employed. The excitation is carried out by monochromatized X‐ray synchrotron radiation from BESSY.