Electronic spectroscopy of ionic clusters

摘要

The electronic transitions of the ionic clusters N$-2$/$+$PLU$/-He$-n$/ (n $EQ 1,2,3), N$-2$/$+$PLU$/-Ne, and N$-2$/O$+$PLU$/-Ne have been detected. The cluster ions, produced by electron impact of a pulsed, seeded supersonic expansion, are mass-selected and injected into an octopole where the electronic transition is induced by a tunable, pulsed laser. The electronic spectra are recorded by detecting the yield of fragment ions, produced by vibrational predissociation within the octopole, in a further quadrupole mass-selector, as a function of the laser wavelength. The spectra show rotational and/or vibrational structure, which has been analyzed to provide information on the structure, binding energies, and vibrational frequencies of these species.