Monomolecular and collision induced processes for the appearance of metastable diatomic ions

The dissociative ionization of carbon monoxide

“…When He is used in a charge exchange reaction with CO, a significant increase in intensity is observed for both the metastable transition and the normal O + peak. These results are interpreted [11] by the formation of O + through the predissociation of a CO + vibronic state.…”

“…Using He + in a charge exchange reaction with CO the intensity of the metastable peak corresponding to CO + (metast.) → C + + O in the first field free region of the double focussing mass spectrometer AEI-MS9 remains unchanged [11]. Furthermore at low ion energies no evidence is found for additional structure due to a predissociation to this limit.…”

“…The energy levels of C and O + are taken from ref. (7) 29.317 C( 3 P) + O + ( 2 P 0 ) (8) 29.746 C( 1 S) + O + ( 2 D 0 ) (9) 30.736 C( 1 D) + O + ( 2 P 0 ) (10) 31.011 C( 5 P 0 ) + O + ( 4 S 0 ) (11) 32.207 C( 5 S 0 ) + O + ( 2 D 0 ) (12) 32.234 C( 1 S) + O + ( 2 P 0 ) (13) 32.430 C( 5 S 0 ) + O + ( 2 P 0 ) (14) 33.928 C( 5 P 0 ) + O + ( 2 D 0 ) (15) 35.532 C( 2 P 0 ) + O + ( 4 S 0 ) (16) 35.987 C( 5 P 0 ) + O + ( 2 P 0 ) (17) 37.226 C( 3 P) + O + ( 4 P) (18) 39.584…”

“…Wankenne and Momigny [11] detected a very weak "metastable transition" at m/e = 9.14 corresponding to the spontaneous decomposition CO + → O + + C in the first field free region of a double focussing mass spectrometer. In this transition a small amount of kinetic energy is involved and a threshold energy has been measured at (25 ± 1) eV.…”

“…Stanton and Monahan [10] published the ion energy spectra of C + and O + at a fixed electron energy. In a double focussing mass spectrometer, Wankenne and Momigny [11] observed metastable transitions corresponding to the formation of C + and O + in the first field free region. Kinetic energy and appearance potentials of these species have been measured.…”