Phenylphosphine

Phenylphosphine is an organophosphorus compound with the chemical formula C₆H₅PH₂. It is the phosphorus analog of aniline. Like other primary phosphines, phenylphosphine has an intense penetrating odor and is highly oxidizable. It is mainly used as a precursor to other organophosphorus compounds. It can function as a ligand in coordination chemistry.

Phenylphosphine

Names
Preferred IUPAC name Phenylphosphane
Other names Phenylphosphine Monophenylphosphine
Identifiers
CAS Number	638-21-1 Y
3D model (JSmol)	Interactive image
ChemSpider	12002 Y
ECHA InfoCard	100.010.297
EC Number	211-325-4
PubChem CID	12519
RTECS number	SZ2100000
UNII	856X9KP929 Y
UN number	2924
CompTox Dashboard (EPA)	DTXSID7073224
InChI InChI=1S/C6H7P/c7-6-4-2-1-3-5-6/h1-5H,7H2 N Key: RPGWZZNNEUHDAQ-UHFFFAOYSA-N N InChI=1/C6H7P/c7-6-4-2-1-3-5-6/h1-5H,7H2 Key: RPGWZZNNEUHDAQ-UHFFFAOYAH
SMILES C1=CC=C(C=C1)P
Properties
Chemical formula	C6H5PH2
Molar mass	110.09 g/mol
Appearance	Colorless liquid
Odor	foul
Density	1.001 g/cm3
Boiling point	160 °C (320 °F; 433 K)
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H250, H301, H311, H315, H319, H331, H335
Precautionary statements	P210, P222, P261, P264, P270, P271, P280, P301+P310, P302+P334, P302+P352, P304+P340, P305+P351+P338, P311, P312, P321, P322, P330, P332+P313, P337+P313, P361, P362, P363, P370+P378, P403+P233, P405, P422, P501
NIOSH (US health exposure limits):
PEL (Permissible)	none[1]
REL (Recommended)	C 0.05 ppm (0.25 mg/m3)[1]
IDLH (Immediate danger)	N.D.[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis

Phenylphosphine can be produced by reducing dichlorophenylphosphine with lithium aluminum hydride in ether:

LiAlH₄ + 2C₆H₅PCl₂ → 2C₆H₅PH₂ + Li⁺ + Al³⁺ + 4Cl⁻

This reaction is performed under a nitrogen atmosphere to prevent side reactions involving oxygen.^[2]

Reactions

Oxidation of phenylphosphine with air affords the oxide.^[2]

C₆H₅PH₂ + O₂ → C₆H₅P(OH)₂

Bis(2-cyanoethylphenyl)phosphine, which is of interest as a synthetic intermediate, can be made from phenylphosphine by base-catalyzed allylic addition to acrylonitrile.

C₆H₅PH₂ + 2CH₂=CHCN → C₆H₅P(CH₂CH₂CN)₂

Bis(2-cyanoethylphenyl)phosphine is a useful precursor to 1-phenyl-4-phosphorinanone by base-induced cyclization followed by hydrolysis. Phosphorinanones can be used to prepare alkenes, amines, indoles, and secondary and tertiary alcohols by reduction, Grignard, and Reformatsky reagents.^[3]

Phenylphosphine reacts with many metal complexes to give complexes and clusters.^[4] It is the precursor to the bridging phosphinidene ligand in certain clusters.

2 (C₆H₅)₂MCl + C₆H₅PH₂ + 3 (C₂H₅)₃N → ((C₆H₅)₂M)₂PC₆H₅ + 3 (C₂H₅)₃N•HCl

Phenylphosphine also have uses in polymer synthesis. Using radical initiations or UV irradiation, polyaddition of phenylphosphine to 1,4-divinylbenzene or 1,4-diisopropenylbenzene will form phosphorus-containing polymers, which have self-extinguishing properties. When mixed with flammable polymers such as polystyrene and polyethylene, the mixed polymer exhibits flame resistant properties.^[5]

References

1. NIOSH Pocket Guide to Chemical Hazards. "#0501". National Institute for Occupational Safety and Health (NIOSH).
2. Freedman, Leon D.; Doak, G. O. (1952). "The Reduction of Benzenephosphonyl Dichloride". Journal of the American Chemical Society. 74 (13): 3414–3415. doi:10.1021/ja01133a504.
3. Snider, Theodore E.; Morris, Don L.; Srivastava, K. C. & Berlin, K. D. (1988). "1-Phenyl-4-Phosphorinanone". Organic Syntheses; Collected Volumes, vol. 6, p. 932.
4. Schumann, Herbert; Schwabe, Peter; Stelzer, Othmar (1969). "Organogermyl, stannyl und plumbylphosphine". Chemische Berichte. 102 (9): 2900–2913. doi:10.1002/cber.19691020904.
5. Obata, Takatsugu; Kobayashi, Eiichi; Aoshima, Sadahito; Furukawa, Junji (1994). "Synthesis of new linear polymers containing phosphorus atom in the main chain by the radical polyaddition: Addition polymers of phenylphosphine with 1,4-divinylbenzene or 1,4-diisopropenylbenzene and their properties". Journal of Polymer Science Part A: Polymer Chemistry. 32 (3): 475–483. Bibcode:1994JPoSA..32..475O. doi:10.1002/pola.1994.080320309.