Guided-ion beam measurements of N++H2O charge-transfer and chemical reaction channels

Guided-ion beam measurements of N++H2O charge-transfer and chemically reactive channels are presented for collision energies ranging from 0.1 eV to 20 eV c.m. The charge-transfer reaction is not as efficient as expected considering the favorable Franck–Condon overlap at resonance. The analysis of product-ion time-of-flight spectra demonstrates that energy transfer is efficient in orbiting collisions at all investigated collision energies. At low collision energies, formation of NO+, and HNO+ and/or NOH+, is observed. The chemically reactive channels exhibit a near 1/ET dependence at low collision energies. Above 0.5 eV, the HNO+/NOH+ cross section drops abruptly below the instrumental sensitivity. The NO+ cross section exhibits a minimum at 1.2 eV, followed by an increase in cross section with energy reaching a maximum of 4×10−16 cm2 at 7 eV before decreasing again. The decline at higher energies is partly attributed to a dissociative loss of the product ions. O+ formation is observed at and above the thermodynamic threshold associated with the O++N+2H asymptotic limit.