2008ApJ...680L..93A

The rotational spectra of HC₄ OH and its deuterated species have been detected in the 17-39 GHz region by microwave spectroscopy. The spectra were generated after pyrolysis of 2-butynol at 830°C; a deuteration reaction to produce DC₄ OH and HC₄OD was caused by mixing the 2-butynol with deuterated water vapor. The rotational constants B and C were precisely determined for HC₄ OH and the rotational constant (B+C)/2 was determined for DC₄ OH and for HC₄OD. With these rotational constants, the entire radio spectrum of HC₄ OH can be accurately estimated to better than 0.42 MHz accuracy at frequencies up to 51.1 GHz. These transition frequencies should be of great use for astronomical identification of this molecule.