Protonation and dehydrogenation during the multiphoton ionization of the cluster: C4H5N(H2O)(n)

Multiphoton ionization (MPI) of the hydrogen-bonded clusters C4H5N-(H2O)(m) was studied with a time of flight (TOF) mass spectrometer at 355 nm. Series of the pyrrole-water cluster ions were observed, including unprotonated cluster ions [C4H5N-(H2O)(n)](+), protonated cluster ions [C4H5N-(H2O)(n)H](+) and dehydrogenated cluster ions [C4H4N-(H2O)(n)](+). Both the experimental and ab initio calculated results agree with that the dehydrogenation has more probabilities to occur while the value of n is raised