Triphenylphosphine dibromide

Triphenylphosphine dibromide
	(C6H5)3PBr+ Br−
Names
	Other names bromotriphenylphosphonium bromide, dibromotriphenylphosphorane
Identifiers
CAS Number	1034-39-5 (incorrect structure);
3D model (JSmol)	Interactive image;
ChemSpider	8312538;
ECHA InfoCard	100.012.596
PubChem CID	10137025;
UNII	7Y0J6R63JD ;
CompTox Dashboard (EPA)	DTXSID3061423 ;
	InChI InChI=1S/C18H15BrP.BrH/c19-20(16-10-4-1-5-11-16,17-12-6-2-7-13-17)18-14-8-3-9-15-18;/h1-15H;1H/q+1;/p-1 Key: UWGULZXZFOYYJT-UHFFFAOYSA-M;
	SMILES C1=CC=C(C=C1)[P+](C2=CC=CC=C2)(C3=CC=CC=C3)Br.[Br-];
Properties
Chemical formula	C18H15Br2P2
Molar mass	453.074 g·mol−1
Appearance	White solid
Density	1.194 g/cm3
Melting point	235 °C (455 °F; 508 K)
Refractive index (nD)	1.6358
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Triphenylphosphine dibromide is the organophosphorus compound with the formula (C₆H₅)₃PBr₂. It is a white or colorless hygroscopic solid that is used as a brominating agent in organic synthesis. It is prepared by the addition of bromine to triphenylphosphine in an inert solvent. Often it is generated in situ.^[1] Triphenylphosphine dibromide is usually depicted as a phosphonium salt with tetrahedral phosphorus cation. According to X-ray crystallography, solid structures can feature halogen bonding.^[2]

Illustrative of its use is the conversion of 2-naphthol to 2-bromonaphthalene:^[3]

C₁₀H₇(OH) + (C₆H₅)₃PBr₂ → C₁₀H₇Br + (C₆H₅)₃PO + HBr

References

↑ Dormoy, Jean-Robert; Castro, Bertrand; Bobinski, Thomas P. (2018). "Triphenylphosphine Dibromide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rt370. ISBN 978-0-471-93623-7.{{cite journal}}: CS1 maint: periodical has ISBN (link)
↑ Nikitin, Kirill; Müller-Bunz, Helge; Gilheany, Declan (2013). "Direct evidence of a multicentre halogen bond: Unexpected contraction of the P–XXX–P fragment in triphenylphosphine dihalides". Chemical Communications. 49 (14): 1434–1436. doi:10.1039/c2cc38363b. hdl:10197/4955. PMID 23322232.
↑ Schaefer, J. P.; Higgins, Jerry; Shenoy, P. K. (1969). "2-Bromonaphthalene". Organic Syntheses. 49: 6. doi:10.15227/orgsyn.049.0006.

[1] Dormoy, Jean-Robert; Castro, Bertrand; Bobinski, Thomas P. (2018). "Triphenylphosphine Dibromide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rt370. ISBN 978-0-471-93623-7.{{cite journal}}: CS1 maint: periodical has ISBN (link)

[2] Nikitin, Kirill; Müller-Bunz, Helge; Gilheany, Declan (2013). "Direct evidence of a multicentre halogen bond: Unexpected contraction of the P–XXX–P fragment in triphenylphosphine dihalides". Chemical Communications. 49 (14): 1434–1436. doi:10.1039/c2cc38363b. hdl:10197/4955. PMID 23322232.

[3] Schaefer, J. P.; Higgins, Jerry; Shenoy, P. K. (1969). "2-Bromonaphthalene". Organic Syntheses. 49: 6. doi:10.15227/orgsyn.049.0006.

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