Knowledge Bank

The ground state rotational spectra of $CD3OH$ and $CH3\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}OH$ have been investigated in the millimeter-wave, range. Transitions in the frequency region between 119 and 176 GHz for $CE3$ OH and between 119 and 167 GHz for $CH318OH$ have been, measured using a source-modulated millimeter-wave spectrometer at the Physikalisch-Chemisches Institut, Giessen. The $CD3OH$ transitions have been assigned based on predicted energy levels arising from the global fit of microwave and far-infrared data to a 55-term Hamiltonian pursued by M.S. Walsh, Li-Hong Xu and R.M, $Leesa$. Comments will be made on the accuracy of these predictions. The measured $CH3\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}OH$ frequencies have been fitted to the more simplified Hamiltonian proposed by $Henningseanb$. An improved set of molecular constants has been determined for $CH3\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}OH$.