Journal of Physical Chemistry A, Vol.123, No.7, 1389-1398, 2019
Soft X-ray Chlorine Photolysis on Chlorobenzene Ice: An Experimental and Theoretical Study
An experimental and theoretical study of the photo-induced homolysis of the carbon-chlorine bond in an ice matrix of chlorobenzene is presented. A condensed chlorobenzene film has been grown in situ and near edge X-ray fine structure (NEXAFS) spectra were collected after exposing the condensed film to a monochromatic photon beam centered at the 2822 eV resonant excitation of chlorine and at 2850 eV. The photoabsorption to the Cl 1s -> sigma* and Cl 1s -> pi* states has been measured and the hypothesis of free radical coupling reactions was investigated via time-dependent density functional theory (TD-DFT) and complete active space self-consistent field (CASSCF) calculations. Also, potential energy pathways to the C-Cl cleavage have been obtained at the CASSCF level to the Cl 1s -> sigma*, 1s -> pi*, and 1s -> infinity states. A strong dissociative character was only found for the Cl 1s -> sigma* resonance.