===== On the Detection of Dicyanides in the ISM =====

 M. Agúndez, C. Bermúdez, C. Cabezas, G. Molpeceres, Y. Endo, N. Marcelino, B. Tercero, J.-C. Guillemin, P. de Vicente, and J. Cernicharo\\
discovered\\
**[[https://doi.org/10.1051/0004-6361/202451525|The rich interstellar reservoir of dinitriles: Detection of malononitrile and maleonitrile in TMC-1]]**\\
//Astron. Astrophys.// **688**, Art. No. L31 (2024).\\
Both molecules were detected in the course of the QUIJOTE line survey of the dark cloud TMC-1 with the Yebes 40 m dish. 
Dicyanomethane or malononitrile was identified through four rotational transitions with modest S/N and partially resolved <sup>14</sup>N HFS splitting and 4 ≤ //J// ≤ 10 and //K<sub>a</sub>// ≤ 1. Other lines are heavily blended or have a lower S/N. //Z//-1,2-Dicyanoethene or maleonitrile was identified through four rotational transitions with modest S/N of which one displayed partially resolved <sup>14</sup>N HFS splitting; one HFS line of another transition is shown as are some blended lines. The quantum numbers were 7 ≤ //J// ≤ 11 and //K<sub>a</sub>// ≤ 1. The abundance ratio of dicyanomethane to //Z//-1,2-dicyanoethene is about 3.5. Related molecules with one CN replaced by CCH are more abundant by varying degrees, consistent with a CCH to CN ration in TMC-1 of about 10.\\
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Contributor(s): H. S. P. Müller; 09, 2024

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