Knowledge Bank

Gaseous HgH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ and HgD$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ 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$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ spectral region using a Fourier transform spectrometer with 0.01 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ resolution. The antisymmetric stretching fundamental bands of HgH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ and HgD$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ were detected at 1912.8 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ and 1375.8 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$, 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$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ and ZnH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$, no perturbation was observed in the HgH$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ bands. The molecular constants and their isotopic ratios will be presented.