Trans- to gauche-transitions in the far infrared spectrum of methanol-D 2 (CHD 2 OH) in the torsional ground state

Successive deuteration in low-mass star-forming regions: The case of D2-methanol (CHD2OH) in IRAS 16293-2422

“…These perpendicular transitions were also reported by Ndao et al (2016). The second (Mukhopadhyay 2016a) and third (Mukhopadhyay 2016c) sets consist of perpendicular transitions assigned in submillimeter wave and FIR spectra: within the ground e 0 torsional state and up to K = 14 for the first set and between the first three torsional states and up to K = 13 for the third set. The torsional subbands with K ≤ 9 were also reported by Ndao et al (2016).…”

The rotation-torsion spectrum of CD2HOH

“…[22] for the K + 1, e 0 ← K, e 0 torsional subbands with 6 ≤ K ≤ 8 are within ±0.002 cm −1 from those listed in the supplementary data associated with our previous investigation [20]. The two wavenumbers given in Table 2 of Mukhopadhyay [23] for the two lowest J-value lines of perpendicular subbands originating from K, e 0 , with K ranging from 3 to 11, agree with the assignments reported in our previous investigation [20] and the present one. The K = 4, o 1 ← 3, e 1 torsional subband reported in Table 3 of Mukhopadhyay and Billinghurst [24] was already reported in our previous investigation [20].…”

“…Several subbands reported in our previous investigation [20] were reported almost at the same time by Mukhopadhyay [21][22][23]. The rotational assignments reported by this author in Tables 1 and 2 of Ref.…”

“…72 torsional subbands could be assigned and the number of available parallel and perpendicular transitions, including those assigned in this work and those reported in Refs. [21,23,24], is 4853. These transitions were fitted simultaneously using the Taylor-type expansions of Eqs.…”

“…It was first spectroscopically investigated by Quade and coworkers [5][6][7]19] using microwave spectroscopy and transitions involving torsional levels up to K = 2 and v t = 6 were assigned. Later, new transitions were recorded in the microwave and far-infrared (FIR) domains [20][21][22][23][24] allowing us to spectroscopically characterize all torsional levels with 3 ≤ K ≤ 9 and v t ≤ 2. Rotation-torsion transitions were analyzed approximating the rotational energy of each torsional state with a J(J +1) Taylor-type expansion.…”