Knowledge Bank

We report here a new high resolution FTIR investigation of the pure rotational spectrum of the $H2Te$ molecule. The spectra were recorded in the region $30-360cm-1$ at temperature between $-40\circ C$ and $-30\circ C$ with a Bruker IFS 120 HR interferometer. Analyses of the pure rotational spectra in the vibrational ground states of the different tellurium-substituted isotopomers have been carried out using an effective Hamiltonian model. Significantly improved molecular parameters have been obtained. One important aim of the present work is the study of the "cluster effect" (i.e., the formation of nearly degenerate, four-member groups of rotation-vibration energy levels at high rotational excitation) in the vibrational ground state of $H2Te$. This effect has been experimentally verified forthe vibrational ground state of $H2Se1$. It has been calculated ab $inition2$ that in the vibrational ground state of $H2Te$, the four highest energy levels at each J value will start to converge towards forming a clusters at $J\approx 12$. Because of the instability of $H2Te$ which necessitates that spectra be recorded at relatively low temperatures, it is difficult to observe transitions involving the cluster states. In the present investigation we have assigned transitions with J > 20. However, the highest $Ka$ value, for which lines could be assigned, was 16. At this $Ka$ value, we have not obtained the "coverage" of the cluster states previously obtained for the $H2Se$ $molecule1$. However we believe that the present study gives a good starting point for further investigations of cluster phenomena in $H2Te$.