Knowledge Bank

High resolution rotational spectra obtained for HF-$\mathrm{<mrow\; data-mjx-texclass="ORD">35</mrow>}Cl2$ and HF-$\mathrm{<mrow\; data-mjx-texclass="ORD">35</mrow>}Cl37Cl$ from molecular beam electric resonance spectroscopy have enabled the spectroscopic constants and dipole moment to be evaluated. The resulting average structure is similar in all respects to that of the anti-hydrogen bonded complex HF-$ClF.1$ The chlorine quadrupole coupling constants determined for this complex show definite distortion of the $Cl2$ electron distribution, and the results will be compared to NQR studies of more strongly bound complexes. The spectroscopic constants are: \def\a{\hphantom{0}} \begin{table}[h] \begin{tabular}{@{}lccccl@{}}\ \a &\multicolumn{1}{c}{$B0(MHz)$} &\multicolumn{1}{c}{$D0(KHz)$} &\multicolumn{1}{c}{$eQqa (inner C1)$} &\multicolumn{1}{c}{$eQqa (outer C1)$} &\multicolumn{1}{c}{$\mu a(D)$}\ \a &\multicolumn{1}{c}{\hrulefill} &\multicolumn{1}{c}{\hrulefill} &\multicolumn{1}{c}{\hrulefill} &\multicolumn{1}{c}{\hrulefill} &\multicolumn{1}{c}{\hrulefill}\ $HF-35Cl2$ &1600.949(1) &2.93(5) &-111.530(17) &-108.161(18) &1.381(2)\ $HF-35Cl37Cl$ &1566.845(1) &2.75(6) &-111.568(8)\a &-\a 85.270(8)\a & $-$\ \end{tabular} \end{table}