From Wikipedia, the free encyclopedia
Jump to: navigation, search
Not to be confused with phosphine.
Kekulé skeletal formula of phosphorine
Aromatic ball and stick model of phosphorine
Systematic IUPAC name
Other names
3D model (Jmol)
MeSH Phosphinine
Molar mass 96.07 g·mol−1
Related compounds
Related -ines


Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Phosphorine (IUPAC name: phosphinine) is a heavier element analog of pyridine, containing a phosphorus atom instead of an aza- moiety. It is also called phosphabenzene and belongs to the phosphaalkene class. It is a colorless liquid that is mainly of interest in research.

Phosphorine is generally stable against air and moisture and can be handled without special air-free techniques. In contrast, silabenzene, a related heavy-element analogue of benzene, is not only air- and moisture-sensitive but also thermally unstable without extensive steric protection.


The first phosphorine to be isolated is 2,4,6-triphenylphosphorine. It was synthesized by Gottfried Märkl in 1966 by condensation of the corresponding pyrylium salt and phosphine or its equivalent ( P(CH2OH)3 and P(SiMe3)3).[2]

Erste Synthese eines Element-homologen Pyridins

The parent (unsubstituted) phosphorine was reported by Arthur J. Ashe III in 1971.[3][4] Ring-opening approaches have been developed from phospholes.[5]

Structure, bonding, and properties[edit]

Structural studies by electron diffraction reveal that phosphorine is a planar aromatic compound with 88% of the aromaticity of that of benzene. Potentially relevant to its high aromaticity are the well matched electronegativities of phosphorus (2.1) and carbon (2.5). The P-C bond length is 173 pm and the C-C bond lengths center around 140 pm and show little variation.[6]

Although phosphorine and pyridine are structurally similar, phosphorines are far less basic. The pKa's of C5H5PH+ and C5H5NH+ are respectively -16.1 and 5.2.[5] Methyl lithium adds to phosphorus in phosphorine whereas it adds to the 2-position of pyridine.[7]

Phosphorine undergoes electrophilic substitution reactions like ordinary aromatic compounds: bromination, acylation, and so on.

Coordination chemistry[edit]

Coordination complexes bearing phosphorine as a ligand are known. Phosphorines can bind to metals through phosphorus center. Complexes of the diphospha analogue of bipyridine are known. Phosphorines also form pi-complexes, illustrated by V(η6-C5H5P)2.[5]

See also[edit]


  1. ^ "Phosphate-Binding Proteolipid - Compound Summary". The PubChem Project. USA: National Center of Biotechnology Information. 
  2. ^ G. Märkl, 2,4,6-Triphenylphosphabenzol in Angewandte Chemie 78, 907–908 (1966)
  3. ^ Ashe, A. J. (1971). "Phosphabenzene and Arsabenzene". Journal of the American Chemical Society. 93 (13): 3293–3295. doi:10.1021/ja00742a038. 
  4. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 544. ISBN 0-08-037941-9. 
  5. ^ a b c François Mathey "Phosphorus Heterocycles" in Modern Heterocyclic Chemistry, First Edition, edited by Julio Alvarez-Builla, Juan Jose Vaquero, José Barluenga, Wiley-VCH, Weinheim, 2011. doi:10.1002/9783527637737.ch23.
  6. ^ László Nyulászi "Aromaticity of Phosphorus Heterocycles" Chem. Rev., 2001, volume 101, pp 1229–1246. doi:10.1021/cr990321x
  7. ^ Ashe III, Arthur J.; Smith, Timothy W. "The reaction of phosphabenzene, arsabenzene and stibabenzene with methyllithium." Tetrahedron Letters 1977, volume 18, pp. 407-410. doi:10.1016/S0040-4039(01)92651-6
  • Quin, L. D. (2000). A Guide to Organophosphorus Chemistry. Wiley-Interscience. ISBN 0-471-31824-8. 

External links[edit]