The pure rotational spectrum and hyperfine structure of CF studied by laser magnetic resonance

Laser magnetic resonance spectra have been measured for four rotational transitions and one spin‐changing transition in the 2Π ground state of CF, generated in an intracavity methane–fluorine flame. From a detailed analysis of the Zeeman hyperfine structure of the J = 9/2→11/2 transition in the Ω = 3/2 spin component the hyperfine constants h, b, and d as well as B0 and q0 have been determined. Using these fitted parameters in conjunction with ab initio results, the values of 〈1/r3〉, 〈(3 cos2ϑ−1)/r3〉, ‖ψ2(0)‖, and 〈(sin2ϑ)/r3〉, averaged over the unpaired electron distribution, have been determined. Comparison of these integrals with those of the fluorine atom indicates that the unpaired electron has approximately 18% F character, implying a substantial degree of double bonding.