Double resonance and high resolution infrared spectroscopy of the CF4 ν3 fundamental. II. Infrared–microwave double resonance and infrared Q-branch spectrum

Abstract

Pure rotational transitions between the v₃ = 1 Coriolis sublevels of CF₄ were observed by infrared–microwave double resonance. A frequency tunable semiconductor diode laser was used as a pumping radiation source. 117 microwave transitions in the J_J+1–J_J, J+1_J+1–J_J, J_J–J−1_J, J_J–J_J−1, and J+1_J–J_J branches were measured within the accuracy of a few tens of kHz. Transitions in the last two branches showed a large systematic frequency shift caused by perturbations fom the 2ν₄ state. The observed pure rotational spectrum was analyzed including the previously measured radio frequency transitions. About 200 infrared ν₃ Q‐branch absorption lines, which were assigned by infrared–radio frequency double resonance, were also analyzed. Eight tensor and nine scalar constants were tentatively determined, including the three ground state constants B₀, D₀, and D₀⁽₄^q₄⁾.