Knowledge Bank

A Balle-Flygare FT-MW spectrometer coupled to a laser ablation source has been used to measure the pure rotational spectra of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$S-CuCl and H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O-CuCl. Both molecules are generated via laser ablation (532 nm) of a metal rod in the presence of CCl$\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}$, argon, a low partial pressure of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$S or H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O and are stabilized by supersonic expansion. Rotational constants and centrifugal distortion constants have been measured for eight isotopologues of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$S-CuCl with substitutions available at the copper, chlorine and hydrogen atoms. Transitions in the spectra of nine isotopologues of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O-CuCl have been measured with isotopic substitutions achieved for every atom. The spectra of both H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$S-CuCl and H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O-CuCl are consistent with a linear arrangement of sulphur or oxygen, metal and chlorine atoms. The structure of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$S-CuCl is pyramidal with $CS$ symmetry. The structure of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O-CuCl is either $C2v$ planar at equilibrium or $CS$ pyramidal but with a low potential-energy barrier to planarity such that the v=0 and 1 states associated with the motion that inverts the configuration at the O atom are well separated. Nuclear quadrupole coupling constants have been measured for the chlorine and copper atoms in each molecule. Nuclear spin-rotation constants have been determined for the copper atom.