Collisional activation experiments protonation

Such behaviour clearly contrasts with the case of 4-iodoaniIine, where protonation in a chemical ionization source occurred not only on the ring but also on the nitrogen atom . Nitrogen protonation was indicated by ion-molecule reactions with dimethyl disulphide consecutive to collisional dehalogenation (FT-ICR experiments) or by an increase in the intensity of the peak at mjz 76 following high-energy collisional activation . 

Organophosphorus Chemistry series regularly lists new mass spectra in the Physical Methods chapter . With this in mind, an approach which considers fundamental aspects of organophosphorus ions (i.e. structure and reactivity) in the gas phase has been adopted. The gas-phase structure and reactivity of ions can be probed via several different techniques, including thermochemical measurements, kinetic energy release of metastable ions, collisional activation mass spectrometry, neutralization reionization mass spectrometry and ion-molecule reactions. An example is the molecule HCP (Table 1) its ionization potentiaP, proton affinity and the IR and rotational spectroscopy of the HCP ion " have all been determined in the gas phase. Another important tool for understanding the structure and reactivity of gas phase ions is ab initio molecular orbital theory. With advances in computational hardware and software, it is now possible to carry out high-level ab initio calculations on smaller systems. Indeed, the interplay between experiment and theory has fuelled many studies ... 

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