M. Agúndez, C. Cabezas, B. Tercero, N. Marcelino, J. D. Gallego, P. de Vicente, and J. Cernicharo
reported on
Discovery of the propargyl radical (CH₂CCH) in TMC-1: One of the most abundant radicals ever found and a key species for cyclization to benzene in cold dark clouds
Astron. Astrophys. 647, Art. No. L10 (2021).
The propargyl radical was identified through the six strongest hyperfine components of the 2₀₂ − 1₀₁ rotational transition around 37460 MHz 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 32.8 and 49.2 GHz. The column density of CH₂CCH is only slightly smaller than that of CH₃CCH, a closed shell species.

Contributor(s): H. S. P. Müller; 05, 2021