| Popis: |
The rotational spectra of two isotopic species of hydrogen sulfide have been revisited. For H2(33)S, which was detected in natural abundance, accurate measurements were performed in the submillimeter-wave region, from 500 GHz up to 1.56 THz, thus allowing improvement of the spectroscopic parameters as well as determination of new high-order centrifugal-distortion constants. The rotational spectrum of the main isotopologue was investigated in the millimeter- and submillimeter-wave region up to 1.6 THz, employing the Lamb-dip technique to obtain sub-Doppler resolution. As a consequence, transition frequencies at 1 THz were retrieved with an accuracy of 1 kHz and the hyperfine structure due to hydrogens was resolved, thus allowing the first determination of the spin–rotation tensor of H in H2S. Improved and new spectroscopic parameters were then provided that allow accurate predictions of rotational transitions up to 20 THz; in particular, the newly determined constants permit prediction of rotational transitions with J < 15, Ka < 12 (up to about 10 THz) with expected uncertainties of a few hundreds of kHz. |
