Knowledge Bank

Two isomers of allyl alcohol have been further studied in selected regions of the submillimeter and microwave spectra. The skew-gauche and syn-gauche conformations have been previously identified at room $temperaturea,b$ and in a $free-jerc$, respectively. The present study positively identifies the syn-gauche conformer in the gas-phase at room temperature and confirms that tunneling, as opposed to internal rotation, of the hydroxyl proton is the predominant perturbation up to $Ka=30$, Further measurements made in the X-band, at kHz precision, have increased the precision of the Coriolis coupling terms an energy level(tunneling) splitting. Extension of the spectral measurements has provided a set of spectral parameters that can accurately predict spectral line frequencies through much of sub-millimeter.