Selectivity in the fragmentation of 1-bromo-2-iodoethane following iodine 4d core electron excitation

Abstract The selectivity in the fragmentation of 1-bromo-2-iodoethane after 4d iodine electron excitation has been investigated by TOF mass spectrometry, photoion—photoion coincidence and synchrotron radiation. Analysis of the results shows that the excitation of the I 4d 5/2,3/2 electrons into the lowest-energy empty σ* orbital leads to an enhancement of the CI and CBr bond breakages when the neutral core hole relaxes both into the mono- and the double-ionization continua. The results are discussed in terms of localization of the positive charges around the CI bond, which was originally excited through the resonances.