Cyaphide


Cyaphide, P≡C−, is the phosphorus analogue of cyanide. It is not known as a discrete salt, however In silico measurements reveal that the −1 charge in this ion is located mainly on carbon, as opposed to phosphorus.

Preparation

Organometallic complexes of cyaphide were first reported in 1992. More recent preparations use two other routes:

From SiR3-functionalised phosphaalkynes

Treatment of the η1-coordinated phosphaalkyne complex trans-+ with an alkoxide resulted in desilylation, followed by subsequent rearrangement to the corresponding carbon-bound cyaphide complex. Cyaphide-alkynyl complexes are prepared similarly.

From 2-phosphaethynolate anion (−OC≡P)

An actinide cyaphide complex can be prepared by C−O bond cleavage of the phosphaethynolate anion, the phosphorus analogue of cyanate. Reaction of the uranium complex with in the presence of 2.2.2-cryptand results in the formation of a dinuclear, oxo-bridged uranium complex featuring a C≡P ligand.