Vibrational relaxation and quenching of CO(A1Π, ν = 0–8) in collisions with rare gas atoms
✍ Scribed by E.H. Fink; F.J. Comes
- Publisher
- Elsevier Science
- Year
- 1974
- Tongue
- English
- Weight
- 646 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
Steady state fluorescence experiments yielded effective cross sections for the vibrational rekvmtion and quenching in collisions of electronica??y excited CO molecules, in single vibrational levels u = 0 to 8 of the A'Ei state, with rare gas atoms. Vibrational relaxation was found to proceed not only by 4u = 1 but also by Au = 2 and Au = 3 processes. The relaxation cross sections for the Au = 1 processes decrease with increasing vibrationat quantum number v. The quenching data give strong evidence for collision induced intersystem crossing to nearby triplet states-Recently, we have reported an experiment which allows systematic studies of the vibrational relaxation and quenching of electronically. excited CO molecules in different vibrationai levels of the A1 II state in collisions with a number of diatomaic molecules and rare gas atoms f 1 ] _ Through resonance absorption of CO(A1 II + Xi zl*) fourth positive (4-t) bands, CO molecules are selectively excited into 9 different vibrational levels (v = C-8) of the A' Ff state. Studies of the ff uorescence spectra in the presence of added atomic or molecular gases yield effective cross sections for the vibrational relaxation as well as for the quenching of the CO molecules in these excited states. In this paper we will discuss the processes which are observed upon the addition of rare gases (He, Ne, Ar, Kr, Xe) to the excited moIecuIes. The effects of molecular gases as Hz, Dz* N2, and CO itself will be discussed in a following paper [Z] .