Cyanophosphaethyne is an unstable molecular compound with structural formula Nâ¡CâÂÂCâ¡P. It can be considered as cyanogen with one nitrogen atom replaced by phosphorus. It has been made as a dilute gas. Cyanophosphaethyne has been tentatively detected in the interstellar medium. Other structural isomers, such as Câ¡NâÂÂCâ¡P (isocyanophosphapropyne), Câ¡C-Nâ¡P (azaphosphadicarbon), and Nâ¡CâÂÂP=C (isocyanophosphavinylidene), have not been observed. The molecule has linear molecular geometry (C<sub>âÂÂv</sub> molecular symmetry).
Cyanophosphaethyne can be produced by heating cyanogen azide and phosphaethyne gases to 700 ðC:
Another method is to heat anhydrous methyl cyanide with anhydrous phosphorus trichloride:
The dipole moment is 3.5 Debye. Having a large dipole makes the molecule easier to detect by certain types of spectroscopy than many other phosphorus containing molecules. The bond lengths are Câ¡N = 1.159 à, CâÂÂC = 1.378 à, and Câ¡P = 1.544 à.