HIGH RESOLUTION INFRARED SPECTRUM 0F HYDROGEN ISOCYANIDE (HNC)

Abstract

Although HNC is always present in HCN in trace amounts, its gas phase spectrum has only recently been observed. We report here the high resolution spectrum of HNC near 3650 $cm^{-1}$ in equilibrium with hot HCN. From an analysis of the $10^{0}0-00^{0}0, 11^{1}0-01^{1}0, 12^{0}0-O2^{0}0$, and $12^{2}0-02^{2}0$ bands we obtain good measurements of a number of ro-vibrational constants including the l-doubling constant q. The rotational constants for the bending vibrations seem to be normal thus leading us to the preliminary conclusion that the molecule shows no quasilinear behavior. From rough intensity measurements at several different temperatures, the energy difference between HNC and HCN can be estimated.