The phosphaethynyl radical, CP, has been detected in five lines of three rotational transitions in the millimeter-wave region:
M. Guélin, J. Cernicharo, G.Paubert, and B. E. Turner,
Free CP in IRC +10216
Astron. Astrophys. 230, L9–L11 (1990).
Contributor(s): H. S. P. Müller; 05, 2007