Knowledge Bank

The pure rotation spectrum of hydrogen Sulfide has been recorded between 50 and $300cm-1$ on a Fourier transform spectrometer with a resolution of $0.005cm-1$. This high resolution and a good signal to noise ratio has allowed a real improvement in the precision of the wavenumbers of the rotational transitions of the three isotopic species$ H_{2}^{32}S$, $H233S$, and $H234S$ observed in natural abundance. Lines with J as high as 22 or $Ka$ as high as l5 have been observed for the most abundant isotope. Then for each isotope, the far infrared rotational transitions together with the available microwave data have been introduced in a least squares fit leading to the determination of precise Watson’s rotational constants. Finally using these constants and a permanent dipole moment D, the absorption of hydrogen sulfide in the far infrared region of the spectrum has been computed.