Cyaphide

Cyaphide, ⁻C≡P, 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 (0.65), as opposed to phosphorus.

Cyaphide anion

−C≡P
Names
IUPAC name Cyaphide
Other names Methanidylidynephosphane
Identifiers
3D model (JSmol)	Interactive image
PubChem CID	101418447
InChI InChI=1S/CP/c1-2/q-1 Key: UVQWQOUGJCVJLT-UHFFFAOYSA-N
SMILES [C-]#P
Properties
Chemical formula	CP−
Molar mass	42.985 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Structure of the first transition metal cyaphide complex, RuH(dppe)₂(CP)

The word "cyaphide" was first coined in 1992, by analogy with cyanide.^[1]

Preparation

Organometallic complexes of cyaphide were first reported in 1992.^[2] More recent preparations use two other routes:

From SiR₃-functionalised phosphaalkynes

Treatment of the η¹-coordinated phosphaalkyne complex trans–[RuH(P≡CSiPh₃)(dppe)₂]⁺ with an alkoxide resulted in desilylation, followed by subsequent rearrangement to the corresponding carbon-bound cyaphide complex.^[3] Cyaphide-alkynyl complexes are prepared similarly.^[4]

From 2-phosphaethynolate anion (⁻O−C≡P)

An actinide cyaphide complex can be prepared by C−O bond cleavage of the phosphaethynolate anion, the phosphorus analogue of cyanate.^[5] Reaction of the uranium complex [((^Ad,MeArO)₃N)U^III(DME)] with [Na(OCP)(dioxane)_2.5] in the presence of 2.2.2-cryptand results in the formation of a dinuclear, oxo-bridged uranium complex featuring a C≡P ligand.

See also

• Phosphaalkyne (R−C≡P)
• Methylidynephosphane (H−C≡P)
• Cyanide
• Cyaarside