Reports on the Detection of 1,3-Pentadiyne in the ISM

The 1,3-pentadiyne molecule CH3C4H, aka methyldiacetylene, had been identified in spectra recorded toward TMC-1 by two groups independently and at almost the same time
J. M. MacLeod, L. W. Avery, N. W. Broten,
The detection of interstellar methyldiacetylene (CH3C4H)
Astrophys. J. 282, L89–L92 (1984);
C. M. Walmsley, P. R. Jewell, L. E. Snyder, and G. Winnewisser,
Detection of interstellar methyldiacetylene (CH3C4H) in the dark dust cloud TMC 1
Astron. Astrophys. 184, L11–L14 (1984).

The molecule was also detected by
M. Araki, S. Takano, N. Sakai, S. Yamamoto, T. Oyama, N. Kuze, and K. Tsukiyama,
who studied
Long Carbon Chains in the Warm Carbon-chain-chemistry Source L1527: First Detection of C7H in Molecular Clouds,
Astrophys. J. 847 Art. No. 51 (2017).
The three J = 11 – 10 transitions with K = 0, 1, and 2 were detected near 44.8 GHz with the 100 m GBT.

Contributor(s): H. S. P. Müller; 7, 2004; 10, 2017