Infrared Laser Spectroscopy of Jet-Cooled C2F6near 10 μm

The ν₅(A_2u) and ν₇(E_u) C–F stretching fundamentals of hexafluoroethane, C₂F₆, have been recorded in a supersonic jet by diode laser absorption spectroscopy. The parallel 5¹_oband is accompanied by five satellite bands, of which three have been assigned to hot bands. A fourth satellite band arises from¹²CF₃¹³CF₃. Transitions satisfying 0 ≤KΔK≤ 7 of the perpendicular 7¹_oband are unperturbed while those having −10 ≤KΔK≤ 7 can be fitted assuming anR_z-Coriolis interaction with a state lying at ν_p= 1256 cm⁻¹. A second localized perturbation affects lines withKΔK≥ 8. The band origins are 1117.10736 (7) cm⁻¹(5¹_o) and 1252.96950 (17) cm⁻¹(7¹_o, 0 ≤KΔK≤ 7), and the rotational constantB₀= 0.0615759 (27) cm⁻¹.