Infrared—ultraviolet double resonance measurements on the relaxation of rotational energy in the (31, 214151) Fermi resonance states of C2H2

✍ Scribed by Michael J. Frost; Ian W.M. Smith

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 522 KB
• Volume: 191
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85591-w

✦ Synopsis

Infrared-ultraviolet double resonance experiments have been performed to measure total rotational relaxation rates from a single, selected level in C2H 2 induced by a variety of collision partners (M). Pulses of tunable infrared radiation from an optical parametric oscillator have been used to excite C2H2 molecules into a rotational level within one or other of the vibrational states arising from Fermi resonance between the zeroth-order 3t and 214t51 sJates. Loss of population from this level was observed by making time-resolved laser-induced fluorescence measurements on the appropriate lines in the A, tAu-X tZg electronic bands of C2H2. Rate constants are presented for relaxation from the j= 12 level of the lower of the Fermi dyads with M = C2H2, He, Ne, Ar, Kr, Xe, H2, N2, 02, CO, NO, HC1, HBr and HCN. A smaller number of results are presented for relaxation from other levels and the data are discussed in the light of energy transfer rates and collision-broadening parameters measured previously for rotational levels in other vibrational states.