High resolution infrared spectroscopy and ab initio calculations of HCN-H-2/D-2 binary complexes

High-resolution infrared laser spectroscopy has been used to study HCN-H-2 and HCN-D-2 complexes in the gas phase. The experimental results are compar ed with ab initio calculations that are also reported here. The latter calc ulations reveal two prominent minima on the potential surface, one correspo nding to a "T-shaped" complex with the H-2 at the hydrogen end of the HCN a nd the other a "linear" complex with the H-2 H-bonded to the nitrogen. The latter minimum is the global minimum on the surface, in agreement with the fact that this structure is observed experimentally for both o-H-2 and p-D- 2. <(C)> 2001 American Institute of Physics.