Dissociative multiple ionization following valence and Si:2p core level photoexcitation of HSi(CH₃)₃ in the range 38-133 eV

Dissociation processes of HSi(CH₃)₃ have been investigated in the valence and Si:2p core-level excitation/ photoionization by photoelectron-photoion coincidence (PEPICO) and photoion-photoion coincidence (PIPICO) techniques together with synchrotron radiation. Various monocations of H⁺, H₂⁺, H₃⁺, CH_n⁺ (n = 0-4), SiCH_n⁺ (n = 0-5), SiC₂H_n⁺ (n = 0-7), and SiC₃H₉⁺ are observed in the whole energy range. Partial ion yield and PIPICO spectra were measured as a function of the incident photon energy in the range 65-133 eV. Ab initio calculations are performed to predict the dissociation pathways and their thermochemistry and to provide estimates of the term values of the core-excited states. The variation of the dissociation pattern with the photon energy is discussed in conjunction with the relevant electronic states.