Knowledge Bank

The microwave spectrum of fluoroacetyl chloride has been studied in order to investigate rotational isomerism about the $C1-C2$ bond. It has been found that the spectrum is dominated by b-type transitions of a rotamer which has the C -- F bond trans with respect to the C -- Cl bond. Rotational constants have been determined for the $\mathrm{<mrow\; data-mjx-texclass="ORD">35</mrow>}Cl$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">37</mrow>}Cl$ isotopic species and lines have been tentatively assigned to the first and second torsional and first bending vibrational state of this $rotamer.35Cl$ Trans Ground Vibrational State [FIGURE]