Radiofrequency and Microwave Spectrum of the Hydrogen Fluoride Dimer; a Nonrigid Molecule

摘要: The radiofrequency and microwave spectra of the K=0 states (HF)2, (DF)2, HFDF have been studied by molecular beam electric resonance method. A unique hydrogen tunnelling motion involving breaking reforming bond causes a splitting rotational energy levels for (HF)2 but not HFDF. dipole selection rules nuclear spin statistics molecules derived from consideration an extended permutation‐inversion group. Rotational constants, tunneling doublings, moments, deuterium quadrupole coupling constants determined observed states. (HF)2(DF)2HFDF(B+C)/2 (MHz)6504.8±2.06252.194±0.0026500.1±0.1ν (MHz)19 776±121579.877 ±0.004μa  (D)2.987±0.0032.9919±0.00063.029±0.003(eqQ)Da (KHz)···110±8270±30 These results are interpreted with semirigid, nonlinear model dimer geometry. F—F distance is 2.79 ± 0.05 A, end fluoride unit bent 60...