C. N. Shingledecker, K. L. K. Lee, J. T. Wandishin, N. Balucani, A. M. Burkhardt, S. B. Charnley, R. Loomis, M. Schreffler, M. Siebert, M. C. McCarthy, and B. A. McGuire
reported on the
Detection of interstellar H₂CCCHC₃N − A possible link between chains and rings in cold cores
Astron. Astrophys. 652, Art. No. L12 (2021).
The observations were obtained in the course of the line survey Green Bank Telescope Observations of TMC-1: Hunting for Aromatic Molecules. The data were recorded with very high resolution which resolves, at least in part, the complex velocity structure. 4,5-Hexadien-2-ynenitrile, or here cyanoacetyleneallene, was indentified through line-stacking with decent signal-to-noise ratio. The molecule has a column density about a factor of 60 lower than that of acetyleneallene. This ratio is similar to that of other pairs of unsaturated hydrocarbons on one hand and cyano derivatives of these on the other.

R. Fuentetaja, C. Cabezas, M. Agúndez, B. Tercero, N. Marcelino, J. R. Pardo, P. de Vicente, and J. Cernicharo
reported on the
Discovery of CH₂CCHC₄H and a Rigorous Detection of CH₂CCHC₃N in TMC-1 with the QUIJOTE Line Survey
Astron. Astrophys. 663, Art. No. L3 (2022).
H₂CCCHC₃N was identified in TMC-1 for the first time through individual lines. The H₂CCCHC₄H to H₂CCCHC₃N ratio was determined as 18 ± 4, somewhat higher than the C₄H to C₃N ratio of ~8.

Contributor(s): H. S. P. Müller; 08, 2021; 07, 2022