Infrared and near infrared emission spectra of TeH and TeD

The vibration-rotation emission spectra for the X²Π ground state and the near infrared emission spectra of the X²Π_1/2-X²Π_3/2 system of the TeH and TeD free radicals have been measured at high resolution using a Fourier transform spectrometer. TeH and TeD were generated in a tube furnace with a DC discharge of a flowing mixture of argon, hydrogen (or deuterium), and tellurium vapor. In the infrared region, for the X²Π_3/2 spin component we observed the 1-0, 2-1, and 3-2 vibrational bands for most of the eight isotopologues of TeH and the 1-0 and 2-1 bands for three isotopologues of TeD. For the X²Π_1/2-X²Π_3/2 transition, we observed the 0-0 and 1-1 bands for TeH and the 0-0, 1-1, and 2-2 bands for TeD. Except for a few lines, the tellurium isotopic shift was not resolved for the X²Π_1/2-X²Π_3/2 transitions of TeH and TeD. Local perturbations with Δv = 2 between the two spin components of the X²Π state of TeH were found: X²Π_1/2, v = 0 with X²Π_3/2, v = 2; X²Π_1/2, v = 1 with X²Π_3/2, v = 3. The new data were combined with the previous data from the literature and two kinds of fits (Hund’s case (a) and Hund’s case (c)) were carried out for each of the 10 observed isotopologues: ¹³⁰TeD, ¹²⁸TeD, ¹²⁶TeD, ¹³⁰TeH, ¹²⁸TeH, ¹²⁶TeH, ¹²⁵TeH, ¹²⁴TeH, ¹²³TeH, and ¹²²TeH.