Investigations of dissociative photoionization of isooctance by synchrotron radiation

Using vacuum ultraviole photons produced by synchrotron radiation and reflection time-of-flight mass spectrometer, dissociative photoionization of isooctane was measured in the photon energy region of 9.7-15.6 ev under ultrasonic molecular beam. Then the dissociative ionization products at different photon energies were obtained. By measuring the photoionization efficiency curves, the appearance potentials of the dominative ion fragments and the vertical ionization energy of isooctane were determined. In addition, combining with G3 calculations we obtained the structure and energy of the parent, neutral and ion fragments. By comparing the experimental measurements with the theoretical calculation, the dissociative photoionization channels of isooctane were elucidated, and formation enthalpies of the fragmented ions and the dissociation energy of the parent ion were obtained. (C) 2013 Elsevier B.V. All rights reserved.