Abstract
The rotational spectra of HC4OH 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 DC4OH and HC4OD was caused by mixing the 2-butynol with deuterated water vapor. The rotational constants B and C were precisely determined for HC4OH and the rotational constant (B + C)/2 was determined for DC4OH and for HC4OD. With these rotational constants, the entire radio spectrum of HC4OH 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.