Journal of Chemical Physics, Vol.117, No.8, 3961-3971, 2002
Site-specific fragmentation caused by core-level photoionization: Effect of chemisorption
We used the energy-selected-photoelectron photoion coincidence (ESPEPICO) method to study site-specific fragmentation caused by C:1s photoionization of 1,1,1-trifluoro-2-propanol-d(1) [CF3CD(OH)CH3, TFIP-d(1)] on a Si(100) surface. High-resolution electron energy loss spectroscopy showed that TFIP-d(1) is dissociatively chemisorbed like (CF3)(CH3)CDO-Si(100), and different chemical shifts at the three carbon sites were observed by photoelectron spectroscopy. The site-specific fragmentation evident in the ESPEPICO spectra of the sub-monolayer at room temperature indicates that the TFIP-d(1) there has an O-Si bond oriented in the trans position with respect to the C-CF3 bond. Here we discuss the fragmentation processes in light of the results obtained with the ESPEPICO method and the Auger-electron photoion coincidence method.