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 (0.65), as opposed to phosphorus.
The word "cyaphide" was first coined in 1992, by analogy with cyanide.[1]
^Jun, Hyoung; Young, Victor G.; Angelici, Robert J. (1992). "A phosphorus analog (C≡P−) of a bridging cyanide (C≡N−) ligand: synthesis and structure of (Cl)(PEt3)2Pt(μ-C≡P)Pt(PEt3)2". Journal of the American Chemical Society. 114 (25): 10064–10065. doi:10.1021/ja00051a050. ISSN0002-7863.