Formyl cyanide, aka cyanoformaldehyde, HC(O)CN, was detected toward Sgr B2(N) in five transitions having J+1_0,J+1 ↔ J_1,J with J = 5 – 9:
A. J. Remijan, J. M. Hollis, F. J. Lovas, W. D. Stork, P. R. Jewell, and D. S. Meier,
Detection of Interstellar Cyanoformaldehyde (CNCHO)
Astrophys. J. 675, L85–L88 (2008).

J. Cernicharo, C. Cabezas, Y. Endo, M. Agúndez, B. Tercero, J. R. Pardo, N. Marcelino, and P. de Vicente
report on
The Sulphur Saga in TMC-1: Discovery of HCSCN and HCSCCH
Astron. Astrophys. 650, Art. No. L14 (2021).
Formyl cyanide was indentified besides these two new and several other molecules. HC(O)CN was identified through 2 a-type transitions with K_a = 0 and J = 4 − 3 or 5 − 4. The identifications were made in the course of an ongoing unbiased molecular line survey between 31.1 and 50.4 GHz using the Yebes 40 m radio telescope. The column density ratio of propynal and formyl cyanide is about 4.

Contributor(s): H. S. P. Müller; 03, 2008; 06, 2021