===== Detection of Protonated Isocyanoacetylene in the ISM =====

 M. Agúndez, C. Cabezas, N. Marcelino, R. Fuentetaja, B. Tercero, P. de Vicente, and J. Cernicharo\\
reported on\\
**[[https://doi.org/10.1051/0004-6361/202243396|A new protonated molecule discovered in TMC-1: HCCNCH<sup>+</sup>]]**\\
//Astron Astrophys.// **659**, Art. No. L9 (2022).\\
Two transitions, //J"// = 3 and 4 near 37.3 and 46.6 GHz, of a new, unknown molecule were detected 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. Subsequently, two additional transitions, //J"// = 8 and 9 near 84.0 and 93.3 GHz, were identified in data from an older IRAM 30 m line survey of TMC-1. Quantum-chemical calculations supported the assignment to HCCNCH<sup>+</sup>.\\

The abundance ratio of HCCCNC to HCCCNCH<sup>+</sup> is ~10. This extremely low ratio is reproduced well with the reaction of C<sup>+</sup> and CH<sub>3</sub>CN being the main source of HCCNCH<sup>+</sup>.\\


----

Contributor(s): H. S. P. Müller 03, 2022

----