The detection of cyano thioformaldehyde (HCSCN) toward TMC-1 was reported in 2021 by Cernicharo and co-workers using the Yebes 40m telescope. A series of a- and b-type lines were observed. Unpublished experimental work by Zaleski and co-workers that was presented in a talk at the 2012 International Symposium on Molecular Spectroscopy was helpful in making the identification. (The conference has since moved from The Ohio State University to the University of Illinois at Urbana-Champaign.)

Cyano thioformaldehyde—or thioformyl cyanide—is the sulfur analog of cyanoformaldehyde, which was detected in 2008. Cyano thioformaldehyde joins a long list of detected cyano compounds.