15min:

M. AFSHARI, M. DEHGHANY, N. MOAZZEN-AHMADI, Department of Physics and Astronomy, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada; A. R. W. MCKELLAR, Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada.

High-resolusion infrared spectra of the weakly bound N₂O-CO₂ complex are studied using a tunable diode laser to probe a pulsed supersonic slit jet. The previously known N₂O-CO₂ dimer band in the region of the ₃ CO₂ asymmetric strtch ( 2350 cm^-1) is remeasured and analyzed in improved detail and two new bands in the regions of the N₂O ₁ ( 2230 cm^-1) and ₃ ( 1280 cm^-1) stretching fundamentals are observed and assigned to N₂O-CO₂. The ground state rotational constants for all three bands are A=0.29498 cm^-1, B=0.05801 cm^-1 and C=0.04837 cm^-1. We also observe another band with c-type rotational structure at about 2251.5 cm^-1 which is assigned as a combination of the intramolecular N₂O ₁ stretching vibration and the intermolecular out-of-plane torsional vibration. The resulting torsional frequency for the N₂O-CO₂ dimer is about 25.7 cm^-1.