phosphirene

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| ImageFile = Phosphirene.png

| ImageSize = 124

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| PIN = 1H-Phosphirene

| SystematicName = Phosphacyclopropene

|Section1={{Chembox Identifiers

| CASNo = 157-19-7

| PubChem = 15786925

| ChemSpiderID = 24771513

| InChI=1S/C2H3P/c1-2-3-1/h1-3H

| InChIKey = BHJIMPINIQQPJX-UHFFFAOYSA-N

| SMILES = C1=CP1 }}

|Section2={{Chembox Properties

| C=2|H=3|P=1

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|Section3={{Chembox Hazards

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Phosphirene is the hypothetical organophosphorus compound with the formula C₂H₂PH. As the simplest cyclic, unsaturated organophosphorus compound, phosphirene is the prototype of a family of related compounds that have attracted attention from researchers.{{cite encyclopedia|encyclopedia=Comprehensive Heterocyclic Chemistry II|year=1996|pages=277–304|volume=1A|title=Phosphiranes, Phosphirenes, and Heavier Analogues|author=François Mathey |author2=Manfred Regitz |doi=10.1016/B978-008096518-5.00008-3|isbn=978-0-08-096518-5}}

Phosphirenes, that is substituted phosphirene compounds where one or more of the H's are replaced by organic substituents, are far more commonly discussed than the parent phosphirene. The first example of a phosphirene, 1,2,3-triphenylphosphirene was prepared via trapping of the phosphinidine complex Mo(CO)₅PPh with diphenylacetylene.{{cite encyclopedia|encyclopedia=J. Am. Chem. Soc.|year=1982|pages=4484–5|volume=104|title=Generation and Trapping of Terminal Phosphinidene Complexes. Synthesis and X-ray Crystal Structure of Stable Phosphirene Complexes|author=Angela Marinetti |author2=Francois Mathey |author3=Jean Fischer |author4=Andre Mitschler |issue=16|doi=10.1021/ja00380a029}}

Placement of the double bond between the carbon atoms provides a 1Hphosphirene in which the phosphorus center is bonded to two carbon atoms and a hydrogen atom. Alternatively, placement of the double bond between the phosphorus center and a carbon atom generates a 2H-phosphirene. The first 2H-phosphirene was synthesized as early as 1987 by Regitz group. However, the chemistry of 2H-phosphirenes was relatively dormant until a series of reports by Stephan group.{{Cite journal|last1=Liu|first1=Liu Leo|last2=Zhou|first2=Jiliang|last3=Cao|first3=Levy L.|last4=Stephan|first4=Douglas W.|date=2018-11-15|title=Facile Cleavage of the P=P Double Bond in Vinyl-Substituted Diphosphenes|journal=Angewandte Chemie International Edition|language=en|volume=58|issue=1|pages=273–277|doi=10.1002/anie.201812592|pmid=30444313|s2cid=53564701 |issn=1521-3757}}{{Cite journal|last1=Liu|first1=Liu Leo|last2=Zhou|first2=Jiliang|last3=Cao|first3=Levy L.|last4=Andrews|first4=Ryan|last5=Falconer|first5=Rosalyn L.

|last6=Russell|first6=Christopher A.|last7=Stephan|first7=Douglas W.|date=2017-12-22|title=A Transient Vinylphosphinidene via a Phosphirene–Phosphinidene Rearrangement|journal=Journal of the American Chemical Society|language=en|volume=140|issue=1|pages=147–150|doi=10.1021/jacs.7b11791|pmid=29272583|hdl=1983/bc270929-86d1-4526-bc0b-803a533312a3 |s2cid=207187997 |url=https://research-information.bris.ac.uk/ws/files/159136895/Full_text_PDF_accepted_author_manuscript_.pdf}}