===== On C6H3N Isomers in the Interstellar Medium =====

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\\
**[[https://doi.org/10.1051/0004-6361/202140698|Detection of interstellar H<sub>2</sub>CCCHC<sub>3</sub>N − 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.\\
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R. Fuentetaja, C. Cabezas, M. Agúndez, B. Tercero, N. Marcelino, J. R. Pardo, P. de Vicente, and J. Cernicharo\\
reported on the\\
**[[https://doi.org/10.1051/0004-6361/202243857|Discovery of CH<sub>2</sub>CCHC<sub>4</sub>H and a Rigorous Detection of CH<sub>2</sub>CCHC<sub>3</sub>N in TMC-1 with the QUIJOTE Line Survey]]**\\
//Astron. Astrophys.// **663**, Art. No. L3 (2022).\\
H<sub>2</sub>CCCHC<sub>3</sub>N was identified in TMC-1 for the first time through individual lines. The H<sub>2</sub>CCCHC<sub>4</sub>H to H<sub>2</sub>CCCHC<sub>3</sub>N ratio was determined as 18 ± 4, somewhat higher than the C<sub>4</sub>H to C<sub>3</sub>N ratio of ~8.\\
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Contributor(s): H. S. P. Müller; 08, 2021; 07, 2022

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