High Resolution Study of the ν2, 2ν1, ν1+ ν3, and 2ν3Bands of Hydrogen Telluride: Determination of Equilibrium Rotational Constants and Structure

Abstract

High resolution Fourier transform spectra of a natural and a130Te monoisotopic sample of H2Te have been recorded at a resolution of 0.0022 cm−1in the 11.6 μm spectral region, as well as a spectrum of a natural sample of H2Te at a resolution of 0.0051 cm−1in the 2.4 μm region. In the 11.6 μm region the main absorbing band is the ν2band, the analysis of which was rather easy. On the other hand, in the 2.4 μm region three bands are absorbing, namely 2ν1, ν1+ ν3, and 2ν3, the last being much weaker than the others. The analysis in this spectral domain was much more difficult because of resonances. Indeed it proved not possible to reproduce the observed lines without taking into account the Darling–Dennison interaction between the levels of the (200) and (002) states and the Coriolis interactions between the levels of (200) and (101) and between those of (101) and (002). Considering these interactions allowed us to calculate very satisfactorily all the experimental levels, and precise sets of vibrational energies and rotational and coupling constants were obtained for the seven most abundant H2Te isotopic species, namely H2130Te, H2128Te, H2126Te, H2125Te, H2124Te, H2123Te, and H2122Te. For the most abundant species, H2130Te, the band centers in cm−1are ν0(ν2) = 860.6563, ν0(2ν1) = 4062.8842, ν0(ν1+ ν3) = 4063.3697, and ν0(2ν3) = 4137.0454. These results, combined with those obtained for other vibrational states, have been used to derive the equilibrium rotational constants and their corrections. Finally, by neglecting the electronic corrections, the equilibrium structure of H2130Te was obtained as follows:re(Te–H) = 1.65145(10) Å, αe(HTeH) = 90.2635(90)°.