MILLIMETER-WAVE SPECTROSCOPY OF $H_{2}$-HCl CLUSTER

$^{a}$D. T. Anderson et al., Chem. Phys. 239, 253-269 (1998)Author Institution: Dept. of Physics, Graduate School of Science, Kyushu University; Devision of Chemistry, Graduate School of Science, Kyushu UniversityThe pure rotational spectrum of the $(p-H_{2})-$ and $(o-H_{2})-HCl$ clusters for both $^{35}Cl$ and $^{37}Cl$ species have been recorded by using pulsed supersonic jet technique and millimeter-wave direct absorption spectroscopy in the 67-166 GHz region. These spectra were searched by using prediction based on the result of the infrared spectrum of the Cl-H stretching $band.^{a}$ For $(p-H_{2})-HCl$, two rotational transitions, $J = 3 - 2, 4 - 3$, in the $\Sigma_{0}$ ground state were obseved. For $(o-H_{2})-HCl$, four rotational transitions split into l-type doubling, $J = 2 - 1 \sim 5 - 4$, in the $\Pi_{0}$ ground state were observed. All of spectra were split into hyperfine structure due to Cl nucleus. The intensity of $(p-H_{2})-HCl$ were approximately 1 / 20 that of $(o-H_{2})-HCl$. The rotatonal constant, $B_{0}$, for the $(p-H_{2})-H^{35}Cl$ and $(o-H_{2})-H^{35}Cl$ were determined to be 16627.2089(20) and 16841.5120(54) MHz, respectively. The analysis of hyperfine structure and the search for rovibrational transions of the vdW bending mode are now in progress