On C7H4 Isomers in the Interstellar Medium

R. Fuentetaja, C. Cabezas, M. Agúndez, B. Tercero, N. Marcelino, J. R. Pardo, P. de Vicente, and J. Cernicharo
reported on the
Discovery of CH<sub>2</sub>CCHC<sub>4</sub>H and a Rigorous Detection of H<sub>2</sub>CCCHC<sub>3</sub>N in TMC-1 with the QUIJOTE Line Survey
Astron. Astrophys. 663, Art. No. L3 (2022).
1,2-Heptadiene-4,6-diyne, also known as propadienylbutadiyne or allenyldiacetylene, was detected with the Yebes 40 m radio telescope between 31.2 and 43.0 GHz. 21 lines with 16 ≤ J ≤ 22 and Ka ≤ 2 were identified as being between unblended and not completely blended. Trot was determined as 9.0 ± 0.5 K. The isoelectronic H2CCCHC3N was identified in TMC-1 for the first time through individual lines. The CH2CCHC4H to H2CCCHC3N ratio was determined as 18 ± 4, somewhat higher than the C4H to C3N ratio of ~8. Similarly, the CH3C6H to CH2CCHC4H ratio is ~0.32, whereas the CH3C4H to CH2CCHC2H ratio is ~1.1.


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