Simultaneous analysis of the 2 nu(2), nu(1), and nu v(3) bands of hydrogen telluride

Spectra of a natural sample of hydrogen telluride as well as a spectrum of monoisotopic H-2 Te-130 have been recorded by means of Fourier transform spectrometry with a resolution of 0.003 cm(-1) in the spectral domain 7.5-4.3 mu m where it is easy to observe the main absorbing bands nu(1) and nu(3). We have located and assigned for the first time the 2 nu(2) band which appears in the lower wavenumber range of the recorded spectral domain near 1700 cm(-1). It proved necessary to treat simultaneously the three states (020), (100), and (001), nu(1) and nu(3) are indeed Coriolis-coupled vibration-rotation bands and it was observed that a few rotational levels of (001) could not be fitted to within their experimental accuracy without considering the second-order Coriolis interaction between the rotational levels of (020) and (001). In this way all the experimental levels were calculated to within the experimental uncertainty, and precise sets of vibrational energies and rotational and coupling constants were obtained for the seven most abundant H2Te isotopic species, namely H-2 Te-130, H-2 Te-128, H-2 Te-126, H-2 Te-125, H-2 Te-124, H-2 Te-123, and H-2 Te-122. For the most abundant isotopic species H-2 Te-130 the bands centers are nu(0)(2 nu(2)) = 1715.9568, nu(0)(v(1)) = 2065.2709, nu(0)(nu(3)) = 2072.1101 cm(-1). (C) 1997 Academic Press.