Carbon monophosphide is a diatomic chemical with formula CP. It is cousin of CS and the cyanide radical (CN). CP and CN are both open-shell species with doublet Π ground electronic states while the ground states of CS and CO are closed-shell. The related anion, CP-, is called cyaphide.
Detection in interstellar medium
The simple diatomic radical carbon monophosphide (CP) was detected in the circumstellar envelope of the star IRC +10216 in 1990. The identification was made by matching 10 rotational lines observed with the IRAM 30m radiotelescope.