CH_3_OCHD_2_ experimental frequencies

Dimethyl ether is one of the most abundant complex organic molecules (COMs) in star-forming regions and their D-to-H (D/H) ratios is important to understand its chemistry and trace the source history. We present the first analysis of doubly-deuterated dimethyl ether (methoxy-d2-methane, 1,1-dideuteromethylether) in its ground- vibrational state, based on an effective Hamiltonian for an asymmetric rotor molecules with internal rotors.

The analysis covers the frequency range 0.15-1.5THz. The laboratory rotational spectrum of this species was measured between 150 and 1500GHz with the Lille's submillimeter spectrometer. For the astronomical detection, we used the Atacama Large Millimeter/submillimeter Array (ALMA) observations from the Protostellar Interferometric Line Survey, PILS.