Charge separation mass spectrometry study of the chloroform molecule following valence and Cl 2p photoionization

Chloroform (HCCl3) molecule has been studied using time-of-flight mass spectrometry in the multi-coincidence mode and synchrotron radiation as the source of photons in the range from 34 to 230 eV, which encompasses the valence level and the Cl 2p edge. Photoionization branching ratios have been measured under efficient ion extraction. Photoelectron photoion coincidence techniques (PEPIPICO, and PEPIPIPICO) have been used in the elucidation of the fragmentation mechanisms of multiply charged molecular ions, formed following the absorption of energetic photons. Observations concerning the molecular fragmentation of the HCCl32+ were attributed to the role of the fast dissociation leading to the release of H atom. It is shown that this unstable doubly charged parent molecule, fragments preferentially via the symmetric mechanism m2+ → m1+ + m2+ + m3 which is mostly driven by Coulomb forces and has the Cl+ + Cl+ + m3 as its major outcome. The dissociation mechanisms for the trication HCCl33+ have also been investigated and are seen to dissociate preferentially into singly charged fragments.