Journal of Chemical Physics, Vol.108, No.18, 7849-7854, 1998
State-specific desorption in condensed Si(CH3)(2)Cl-2 following resonant excitation at the Cl 2p edge
Photon-stimulated ion desorption (PSID) from solid Si(CH3)(2)Cl-2 following Cl 2p core-level excitation has been investigated along with the resonant photoemission spectra using synchrotron radiation. The Cl L-23-edge total-electron yield spectrum of solid Si(CH3)(2)Cl-2 mainly exhibits the Cl 2p --> 15a(1)* Cl 2p --> 10b(1)* and shape resonance peaks. A significant dissimilarity between the Cl L-23-edge total-electron yield spectrum and Cl+ PSID spectrum of solid Si(CH3)(2)Cl-2 is observed. The desorption of atomic Cl+ ions is detected predominantly at the Cl 2p --> 15a(1)* excitation, while scarcely any Cl+ ions are observed following the Cl 2p --> 10b(1)* excitation and Cl 2p --> shape resonance excitation. This indicates that the character of bound terminating orbital has a significant influence on the desorption processes. The enhanced Cl+ desorption yield at the Cl 2p --> 15a(1)* resonance is attributed to the the fast desorption process originating from the localization of the spectator electron in the strong antibonding orbital.
Keywords:SITE-SPECIFIC FRAGMENTATION;X-RAY-ABSORPTION;CORE-LEVEL PHOTOEXCITATION;ATOMIC AUGER-SPECTRA;NARROW-BAND METALS;ION DESORPTION;SYNCHROTRON-RADIATION;STIMULATED DESORPTION;ELECTRONIC-STRUCTURE;ADSORBED WATER