C. Cabezas, M. Agúndez, N. Marcelino, B. Tercero, J. R. Pardo, P. de Vicente, and J. Cernicharo
reported on the
Discovery of Interstellar 3-Cyanopropargyl Radical, CH₂CCCN
Astron. Astrophys. 654, Art. No. L9 (2021).
ortho-CH₂C₃N was identified through three a-type transitions with J = 8 − 7 to 10 − 9 and K_a = 0 in the course of a molecular line survey of the prototypical cold dark molecular cloud TMC-1 carried out with the Yebes 40 m radio telescope between 31.0 and 50.4 GHz. These transitions displayed partially resolved fine and hyperfine structure splitting; few components were blended by lines of other species. Also observed were four transitions of para-CH₂C₃N with J = 8 − 7 or 9 − 8 and K_a = 1, which displayed well resolved fine structure splitting; some of these lines were also blended. A value of T_rot = 7 ± 1 K was derived. The column density of CH₂C₃N is about a factor of 100 lower than that of CH₂CN. And while CH₂C₃N is roughly a factor of 10 less abundant than CH₃C₃N, CH₂CN is more abundant than CH₃CN by a factor of about 3.

Contributor(s): H. S. P. Müller; 11, 2021