Microwave l-type resonance transitions of the v6 = 1 state in CHF3 and CDF3: Accidental degeneracy and molecular structure

Observations of the direct l-type resonance transitions in the microwave spectrum of the v₆ = 1 state of CHF₃ and CDF₃ have been extended to J = 37. Accidental degeneracies were found between J = 34, $\text{K}\text{= 3}\text{and}\text{0}$ in both molecules enabling the C rotational constants of CHF₃ and CDF₃ to be determined, using 118 observed frequencies for CHF₃ and 104 for CDF₃. After suitable correction the B and C rotational constants were used to determine the r₀, r₂, and r_e structures for CHF₃ and CDF₃.The equilibrium structure was determined to be $\text{CH}\text{= 1.091 ± 0.014}\text{A}\text{?}$, $\text{CF}\text{= 1.3284 ± 0.0031}\text{A}\text{?}$ and ∠FCF = 108.58 ± 0.34°.