A comparison of the charge transfer and collisional activation processes in collisions between keV He+ and CO2

作者：Lin Yawei; Mayer Paul M^*

来源：Chemical Physics, 2010, 378(1-3): 103-109.

DOI：10.1016/j.chemphys.2010.10.009

• Frank-Condon principle
• Collision-induced emission
• Collisional activation
• Mass spectrometry
• Charge-transfer reaction

A commercial mass spectrometer coupled with a spectrograph and charge-coupled device (CCD) was used to obtain the collision-induced emission (CIE) spectra (190-1020 nm) from 4 to 8 keV collisions between projectile He+center dot ions and CO2 target gas (He+center dot/CO2). The observed emissions were from the A(2)Pi(+)(u) and B-2 Sigma(+)(u) states of CO2+center dot , excited states of He, along with excited fragments. The relative vibrational population of the A(2)Pi(+)(u) state were estimated and compared with our previous CO2+center dot/He studies. The results indicate that charge transfer ionization of CO2 in He+center dot/CO2 collisions is similar to that of photoexcitation, while in the case of CO2+center dot/He, the population is more evenly distributed due to intramolecular vibrational redistribution (IVR) after the collision. Adiabatic potential energy surfaces calculated at the CISD/6-311+g(2df) level of theory for CO2+center dot/He collisions, show the curve crossing of the CO(2)(+center dot)A(2)Pi(+)(u) and CO2+center dot B2 Sigma(+)(u) states, in agreement with our observation.

• 出版日期2010-12-9