Energetics of fragmentations of indene dication from photoionization experiments

Abstract: The formation and fragmentation of the indene dication is studied using synchrotron radiation. The double-ionization energy of indene amounts to 21.8±0.1eV. The appearance energies of the fragments and are 25.8±0.1eV and 25.7±0.2eV, respectively. Although the appearance energies are almost the same, the dicationic fragment is formed in a higher yield than . It is suggested that the elimination of atomic hydrogen is associated with a considerable energy barrier, whereas the H2 elimination proceeds via very small barrier or is barrier-less process with respect to the reaction endothermicity. [Copyright &y& Elsevier]