Stark and Frequency Measurements in the FIR Spectrum of H2O2

The submillimeter-wave spectrum of H2O2has been recorded by means of a tunable FIR spectrometer. Stark measurements have been performed on three selected transitions in then= 0 state, namely, the 220–110(τ = 4 ← 2) at 1 272 297 MHz, the 826–716(τ = 1 ← 3) at 882 451 MHz, and the 928–818(τ = 1 ← 3) at 962 933 MHz. Accurate values of the transition dipole moments of the molecule have been derived by considering the interaction between the levels involved in the transition and the close near-resonant levels. About 40 new lines, belonging to therQ4andrQ5subbranches of the rotational transitions between the lowest torsional states (τ = 1, 2, 3, 4n= 0), have been measured in the 2.8 and 3.4 THz spectral regions and analyzed together with the previously measured millimeter- and submillimeter-wave, as well as IR, transitions.