Comprehensive analysis of Isobutyraldehyde: millimetre-wave spectroscopy as an approach to ISM detection

Abstract

Iso-butyraldehyde is a strong candidate for ISM search, for which GEM is willing to provide spectroscopical information. Out of four possible rotational conformations, only the gauche and trans rotamers are stable. In a 75 to 325 GHz frequency range analysis, more than 3800 transitions corresponding to the most stable (gauche) specie in the vibrational ground state were assigned. Only 394 transitions of the trans conformer could be assigned as a result of a mismatching between the observed and predicted frequencies. The high number of observed transitions led to precise determination of rotational, quartic and first complete set of sextic centrifugal distortion constants using Watson’s-A Hamiltonian reduction. These accurate parameters could allow the detection of iso-butyraldehyde in the ISM.