J. Cernicharo, R. Fuentetaja, C. Cabezas, M. Agúndez, N. Marcelino, B. Tercero, J. R. Pardo, and P. de Vicente
reported on the
Discovery of five cyano derivatives of propene with the QUIJOTE line survey
Astron. Astrophys. 663, Art. No. L5 (2022).
The molecular line survey is of the prototypical cold dark molecular cloud TMC-1 and was carried out with the Yebes 40 m radio telescope between 31.0 and 50.4 GHz. 2-Butenenitrile, aka 1-cyanopropene or crotononitrile, was detected in its E (or trans) and Z (or cis) stereoisomeric forms. In addition, 2-propenenitrile, aka 2-cyanopropene or methacrylonitrile was also identified as was 3-Butenenitrile, aka 3-cyanopropene or allyl cyanide, in its syn (or cis) and gauche conformers. Several a-type transitions having 4 ≤ J ≤ 8 to 6 ≤ J ≤ 11 and K_a ≤ 2 were identified. A value of T_rot = 7 ± 1 K was derived through a rotation diagram in all instances. The column density of butenyne is about a factor of 4.5 higher than that of the isoelectronic allenyl cyanide. It is, in addition, similar to that of butenyne, a factor of 5 lower than that of the methyldiacetylene isomer (aka butadienyne), and a factor of 10 lower than that of methylacetylene (aka propyne).

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