THE VIBRATION-ROTATION EMISSION SPECTRA OF HgH$_{2}$ AND HgD$_{2}$

Abstract

Gaseous HgH$_{2}$ and HgD$_{2}$ were observed for the first time in a discharge of mercury vapor and molecular hydrogen at room temperature. The emission spectra were recorded in the $1200-2200$ cm$^{-1}$ spectral region using a Fourier transform spectrometer with 0.01 cm$^{-1}$ resolution. The antisymmetric stretching fundamental bands of HgH$_{2}$ and HgD$_{2}$ were detected at 1912.8 cm$^{-1}$ and 1375.8 cm$^{-1}$, respectively, and lines from the six naturally abundant isotopes of mercury were completely resolved. The $002 - 001$ and $011 - 010$ hot bands were also analyzed for both molecules. Unlike CdH$_{2}$ and ZnH$_{2}$, no perturbation was observed in the HgH$_{2}$ bands. The molecular constants and their isotopic ratios will be presented.