HYBRIDIZATION OF THE ROTATIONAL STATE OF HD ADSORBED ON POROUS MATERIALS - POROUS VYCOR GLASS AND MGO

We present measurements of the infrared absorption corresponding to the roto-vibrational transitions of HD adsorbed in Porous Vycor Glass and MgO pills. For glass the absorption line bandwidths at low coverages of HD are more than two times larger than those of adsorbed H2 and D2. Also, we observe the transitions corresponding to deltaJ=3 and deltaJ=5, whereas only the allowed deltaJ=0, +/-2 are observed for the pure isotopes. HD is a molecule possessing spherical symmetry whose center-of-mass is asymmetrically located. Our observations strongly suggest hindrance of the rotational states of HD which may be attributed to the hybridization of rotations and adsorbed HD phonons resulting from the molecule mass-asymmetry. Results for HD on MgO are simmilarly analyzed and will be discussed also.