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 location mainly on carbon (0.65), as opposed to phosphorus.
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-[RuH(P≡CSiPh3)(dppe)2]+ 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 [((Ad,MeArO)3N)UIII(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.
- phosphaalkyne (P≡CH)
- Robert J. Angelici (2007). "Cyaphide (C≡P−): The Phosphorus Analogue of Cyanide (C≡N−)". Angew. Chem. Int. Ed. 46: 330–332. doi:10.1002/anie.200603724.
- Cordaro; et al. (2006). "Making the True "CP" Ligand". Angewandte Chemie International Edition. 45: 6159–6162. doi:10.1002/anie.200602499.
- Trathen; et al. (2014). "Synthesis and electronic structure of the first cyaphide-alkynyl complexes". Dalton Transactions. 43: 9004–9007. doi:10.1039/C4DT01108B.
- Christopher J. Hoerger, Frank W. Heinemann, Elisa Louyriac, Laurent Maron, Hansjörg Grützmacher, Karsten Meyer (2017). "Formation of a Uranium-Bound η1-Cyaphide Ligand via Activation and C−O Bond Cleavage of Phosphaethynolate". Organometallics. 36: 4351–4354. doi:10.1021/acs.organomet.7b00590.CS1 maint: Multiple names: authors list (link)