methylidynephosphane

Methylidynephosphane (phosphaethyne) is a chemical compound with the chemical formula . It was the first phosphaalkyne compound discovered, containing the unusual C≡P carbon-phosphorus triple bond. Although isolated samples of methylidynephosphane are impractical, other derivatives have been well studied such as tert-butylphosphaacetylene. The conjugate base of methylidynephosphane is cyaphide.

==Description== Methylidynephosphane is the phosphorus analogue of hydrogen cyanide, with the nitrile nitrogen replaced by phosphorus. Methylidynephosphane can be synthesized via the reaction of phosphine with carbon, but it is extremely reactive and polymerises readily at temperatures above −120 °C. However, several types of derivatives, with bulky groups, such as tert-butyl or trimethylsilyl, substituted for the hydrogen atom, are much more stable, and are useful reagents for the synthesis of various organophosphorus compounds. The (cyaphate) and (thiocyaphate) anions are also known.