MILLIMETER-WAVE SPECTRUM OF HYDROGEN PEROXIDE

Some 50 rotational transitions of HOOH in the ground vibrational state have been measured in the millimeter-wave region from 60 to 300 kMc/sec. Analysis of these transitions provides a complete set of values of the rotational constants and the accurate value of 342 885.0±2.0 Mc/sec for the doublet splitting of the ground-state vibrational levels by internal barrier tunneling. The rotational constants in the Hamiltonian for the semirigid-rotor model with an internal axis of rotation are (in megacycles per second): ν 01.201.2=276208.0±2.0, ν03.4 03.4=275912.7±2.0, β01.201.2=25662. 1±2.0, β03.403.4=25673.7±2.0, γ01.201.2=542.96±0.5, γ 03.403.4=476.64±0.5. The dihedral angle of the OH bonds is found to be 120°1′±15′ for the lower level and 116°7′±15′ for the upper level of the ground-state doublet. Some 30 millimeter-wave rotational transitions for DOOD were also measured, but analysis of them is not yet complete.