- The publication
Rotational Spectroscopy as a Tool to Study Vibration-Rotation Interaction: Investigations of
13CH3CN and CH313CN up to v8 = 2
and a Search for v8 = 2 Transitions toward Sagittarius B2(N) demonstrates
the capabilities of rotational spectroscopy in the cases of symmetric top molecules.
Near-degeneracies within v8 = 2 provided a very good handle on the energy spacings
between the l = 0 and l = ±2 substates. Such interactions are fairly common in
degenerate overtone states, but energy levels get particularly close in the present cases.
Rarer are ΔK = 0, Δl = 3 interactions such as the ones between
v8 = 1 and 2, which were already known for the main isotopolog from an earlier study.
A resonant ΔK = ±2, Δl = ∓1 interaction between
v8 = 1 and 0 was accessed for 13CH3CN, as earlier for CH3CN;
the interacting Js are too high in the case of CH313CN.
- Two articles highlight the value of collaboration in reciprocal manners. Measurements and assignments for
Investigation of the Rotational Spectrum of
CH317OH and its Tentative Detection toward Sagittarius B2(N) were carried out in
Köln, and Vadim Ilyushin in Charkiw, Ukraine, performed the analyses emplyoing his RAM36hf program.
Arnaud Belloche from Bonn contributed ALMA data for its tentative detection.
In the case of
Submillimeter-wave Spectroscopy of the
CH3O Radical, measurements and assignments were made in Orsay, France, along with initial analyses.
The final analyses were carried out by me. The analyses were challenging in both projects because of the plethora
of allowed spectroscopic parameters.
- The investigation Rotational Spectroscopy
of the Thioformaldehyde Isotopologues H2CS and H2C34S in Four Interacting Excited
Vibrational States and an Account on the Rotational Spectrum of Thioketene, H2CCS is a text book
example for Coriolis interaction. The study highlights the importance of rotational spectroscopy for deeper insight
into rovibrational interactions as does the preceeding work on methyl cyanide. The preceding publication
Laboratory Spectroscopic Study of Isotopic
Thioformaldehyde, H2CS, and Determination of its Equilibrium Structure is also recommended.
- Toward a Global Model of the Interactions in Low-lying States of
Methyl Cyanide: Rotational and Rovibrational Spectroscopy of the v4 = 1 State and Tentative Interstellar Detection
of the v4 = v8 = 1 State in Sgr B2(N).
This work describes an exploration of the intricate interactions of v4 = 1 with neighboring states,
in paricular with v8 = 2 and 3. An ealier account was given in
Rotational Spectroscopy as a Tool to Investigate Interactions between
Vibrational Polyads in Symmetric Top Molecules: Low-lying States v8 ≤ 2 of Methyl Cyanide, CH3CN.