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Diphosphorus tetrafluoride
Names
	IUPAC name difluorophosphanyl(difluoro)phosphane
	Other names tetrafluorodiphosphine; phosphorus difluoride
Identifiers
CAS Number	13824-74-3;
3D model (JSmol)	Interactive image;
ChemSpider	123129;
PubChem CID	139615;
CompTox Dashboard (EPA)	DTXSID00160552 ;
	InChI InChI=1S/F4P2/c1-5(2)6(3)4 Key: PCIAPVMJDQUHAP-UHFFFAOYSA-N;
	SMILES FP(F)P(F)F;
Properties
Chemical formula	F4P2
Molar mass	137.941136648 g·mol−1
Melting point	−86.5 °C (−123.7 °F; 186.7 K)
Boiling point	−6.2 °C (20.8 °F; 266.9 K)
Related compounds
Other anions	Diphosphorus tetrachloride; Diphosphorus tetrabromide; Diphosphorus tetraiodide
Other cations	dinitrogen tetrafluoride; diarsenic tetrafluoride
Related Binary Phosphorus halides	phosphorus trifluoride; phosphorus pentafluoride
Related compounds	diphosphane; diphosphines
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Diphosphorus tetrafluoride is a gaseous compound of phosphorus and fluorine with formula P₂F₄. Two fluorine atoms are connected to each phosphorus atom, and there is a bond between the two phosphorus atoms. Phosphorus can be considered to have oxidation state +2, as indicated by the name phosphorus difluoride.^[1]

Production

Diphosphorus tetrafluoride was discovered in 1966 by Max Lustig, John K. Ruff and Charles B. Colburn at the Redstone Research Laboratories. The initial synthesis reacted phosphorus iododifluoride with mercury at room temperature.^[2]

2PF₂I +2Hg → P₂F₄ + Hg₂I₂

Properties

The P−P bond in diphosphorus tetrafluoride is much stronger than the corresponding N−N bond in dinitrogen tetrafluoride which easily breaks into nitrogen difluoride.^[2]

The infrared spectrum has absorption at 842 cm⁻¹, 830 cm⁻¹, 820 cm⁻¹, and weaker at 408 cm⁻¹ and 356 cm⁻¹.^[2]

The molecule has C_2h symmetry.^[3]

Reactions

Under ultraviolet light diphosphorus tetrafluoride reacts with alkynes connected to trifluoromethyl groups to add difluorophosphino (-PF₂) groups on each side of a double bond. Other kinds of alkynes produced polymers with this treatment.^[4] With alkenes, similarly bis(difluorophosphino) is added across the double bond.^[5]

Diphosphorus tetrafluoride reacts with diborane to yield another gas P₂F₄•BH₃ which does not condense above −85°C. This decomposes to yet another gas PF₃•BH₃ and a polymer with formula PF.^[6]

Diphosphorus tetrafluoride reacts with oxygen or water to yield diphosphorus tetrafluoride oxide, which has one oxygen atom inserted between the two phosphorus atoms:^[2]^[7]

{\ce {2P2F4{}+H2O\to 2PHF2{}+F2POPF2}}

The latter compound is a gas with boiling point around −18°C.

References

^ Toy, Arthur D. F. (2016). The Chemistry of Phosphorus: Pergamon Texts in Inorganic Chemistry. Elsevier. p. 418. ISBN 978-1-4831-3959-3.
^ ^a ^b ^c ^d Lustig, Max; Ruff, John K.; Colburn, Charles B. (August 1966). "Diphosphorus Tetrafluoride and Diphosphorus Oxytetrafluoride". Journal of the American Chemical Society. 88 (16): 3875. doi:10.1021/ja00968a046.
^ Rhee, Kee H.; Snider, A.Monroe; Miller, Foil A. (June 1973). "Infrared and Raman spectra and structure of P2F4". Spectrochimica Acta Part A: Molecular Spectroscopy. 29 (6): 1029–1035. Bibcode:1973AcSpA..29.1029R. doi:10.1016/0584-8539(73)80142-4.
^ Morse, J.G.; Mielcarek, J.J. (July 1988). "Photoreactions of tetrafluorodiphosphine with alkynes". Journal of Fluorine Chemistry. 40 (1): 41–49. doi:10.1016/S0022-1139(00)81060-X.
^ Morse, Joseph G.; Morse, Karen W. (March 1975). "Photoreactions of tetrafluorodiphosphine with nonsubstituted olefins and perfluoroolefins". Inorganic Chemistry. 14 (3): 565–569. doi:10.1021/ic50145a024.
^ Morse, Karen W.; Parry, Robert W. (January 1967). "The Basic Properties of Tetrafluorodiphosphine. The Synthesis of Tetrafluorodiphosphine Borane". Journal of the American Chemical Society. 89 (1): 172–173. doi:10.1021/ja00977a049.
^ Rudolph, R. W.; Taylor, R. C.; Parry, R. W. (August 1966). "Fluorophosphine Ligands. III. Syntheses Involving PF I. The Preparation and Characterization of μ-Oxo-bisdifluorophosphine, Cyanodifluorophosphine, and Tetrafluorodiphosphine". Journal of the American Chemical Society. 88 (16): 3729–3734. doi:10.1021/ja00968a010. PMID 5916370.

[1] Toy, Arthur D. F. (2016). The Chemistry of Phosphorus: Pergamon Texts in Inorganic Chemistry. Elsevier. p. 418. ISBN 978-1-4831-3959-3.

[Lust-2] Lustig, Max; Ruff, John K.; Colburn, Charles B. (August 1966). "Diphosphorus Tetrafluoride and Diphosphorus Oxytetrafluoride". Journal of the American Chemical Society. 88 (16): 3875. doi:10.1021/ja00968a046.

[3] Rhee, Kee H.; Snider, A.Monroe; Miller, Foil A. (June 1973). "Infrared and Raman spectra and structure of P2F4". Spectrochimica Acta Part A: Molecular Spectroscopy. 29 (6): 1029–1035. Bibcode:1973AcSpA..29.1029R. doi:10.1016/0584-8539(73)80142-4.

[4] Morse, J.G.; Mielcarek, J.J. (July 1988). "Photoreactions of tetrafluorodiphosphine with alkynes". Journal of Fluorine Chemistry. 40 (1): 41–49. doi:10.1016/S0022-1139(00)81060-X.

[5] Morse, Joseph G.; Morse, Karen W. (March 1975). "Photoreactions of tetrafluorodiphosphine with nonsubstituted olefins and perfluoroolefins". Inorganic Chemistry. 14 (3): 565–569. doi:10.1021/ic50145a024.

[6] Morse, Karen W.; Parry, Robert W. (January 1967). "The Basic Properties of Tetrafluorodiphosphine. The Synthesis of Tetrafluorodiphosphine Borane". Journal of the American Chemical Society. 89 (1): 172–173. doi:10.1021/ja00977a049.

[7] Rudolph, R. W.; Taylor, R. C.; Parry, R. W. (August 1966). "Fluorophosphine Ligands. III. Syntheses Involving PF I. The Preparation and Characterization of μ-Oxo-bisdifluorophosphine, Cyanodifluorophosphine, and Tetrafluorodiphosphine". Journal of the American Chemical Society. 88 (16): 3729–3734. doi:10.1021/ja00968a010. PMID 5916370.

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