Difference between revisions of "Oxygen difluoride"
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{{chembox | {{chembox | ||
| + | | IUPACName = Oxygen difluoride | ||
| + | | OtherNames = Difluorine monoxide<br/>Difluorooxidane<br/>Difluoridooxygen | ||
| Section1 = {{Chembox Identifiers | | Section1 = {{Chembox Identifiers | ||
| ChemSpiderID = 22593 | | ChemSpiderID = 22593 | ||
| Line 22: | Line 24: | ||
| DeltaHf = +24.52 kJ mol<sup>−1</sup> | | DeltaHf = +24.52 kJ mol<sup>−1</sup> | ||
| Entropy = 247.46 J K<sup>−1</sup> mol<sup>−1</sup> | | Entropy = 247.46 J K<sup>−1</sup> mol<sup>−1</sup> | ||
| + | }} | ||
| + | | Section8 = {{Chembox Related | ||
| + | | OtherFunctn = [[Dioxygen difluoride]] | ||
| + | | Function = [[fluorides of oxygen]] | ||
| + | | OtherCpds = [[Dichlorine monoxide]]<br/>[[Dibromine monoxide]] | ||
}} | }} | ||
}} | }} | ||
| − | '''Oxygen difluoride''', OF<sub>2</sub>, sometimes known as '''difluorine monoxide''', is the most stable of the binary compounds of [[oxygen]] and [[fluorine]].<ref name="G&E"/> | + | '''Oxygen difluoride''', OF<sub>2</sub>, sometimes known as '''difluorine monoxide''',{{#tag:ref|Fluorine is more [[Electronegativity|electronegative]] than oxygen, both on the normal numerical scales<ref>{{Allred (1961)}}.</ref> and on the conventional series used in inorganic nomenclature,<ref>{{RedBook2005|page=260}}.</ref> so OF<sub>2</sub> is usually considered a fluoride of oxygen and not an oxide of fluorine. However, other X<sub>2</sub>O compounds (X = Cl, Br) are considered to be halogen oxides, and so F<sub>2</sub>O is sometimes considered to be a member of this series, despite its somewhat different chemistry.<ref name="C&W">{{Cotton&Wilkinson5th|pages=454–56}}.</ref>|group=note}} is the most stable of the binary compounds of [[oxygen]] and [[fluorine]].<ref name="G&E"/><ref name="C&W"/> It was discovered as a byproduct of fluorine production using [[Moissan cell]]s ([[electrolysis]] of [[Hydrogen fluoride|HF]]/[[Potassium fluoride|KF]]) due to small amounts of water in the electrolyte.<ref>{{citation | last1 = Lebeau | first1 = P. | last2 = Damiens | first2 = A. | title = Sur l'existence d'un composé oxygéné du fluor | journal = C. R. Hebd. Acad. Sci. Paris | year = 1927 | volume = 185 | pages = 652–54 | url = http://gallica.bnf.fr/ark:/12148/bpt6k31384/f652.image}}.</ref> A more satisfactory method of preparation is the reaction of fluorine with 2% aqueous [[sodium hydroxide]] solution followed by [[fractional distillation]] of the gas produced.<ref>{{citation | last1 = Lebeau | first1 = P. | last2 = Damiens | first2 = A. | title = Sur un nouveau mode de préparation du fluorure d'oxygène | journal = C. R. Hebd. Acad. Sci. Paris | year = 1929 | volume = 188 | pages = 1253–55 | url = http://gallica.bnf.fr/ark:/12148/bpt6k31417/f1253.image}}.</ref><ref>{{citation | last = Yost | first = D. M. | title = Oxygen Fluoride | journal = Inorg. Synth. | year = 1939 | volume = 1 | pages = 109–11}}.</ref><ref>{{citation | title = Concerning the mechanism of formation of oxygen difluoride | first1 = Evan H. | last1 = Appelman | first2 = Albert W. | last2 = Jache | journal = J. Am. Chem. Soc. | year = 1987 | volume = 109 | issue = 6 | pages = 1754–57 | doi = 10.1021/ja00240a026}}.</ref> |
| + | |||
| + | ==Structure== | ||
| + | Oxygen difluoride has a bent ''C''<sub>2v</sub> structure as expected by [[VSEPR theory]]. The oxygen–fluorine bond length is 140.5 pm and the bond angle at oxygen is 103°, consistent with single bonding and sp<sup>3</sup> hybridization at oxygen.<ref name="G&E"/><ref name="C&W"/> | ||
| + | |||
| + | {| class=wikitable | ||
| + | |- | ||
| + | ! | ||
| + | ! ''r''(O–X)/pm | ||
| + | ! X–O–X/° | ||
| + | ! | ||
| + | ! | ||
| + | ! ''r''(O–X)/pm | ||
| + | ! X–O–X/° | ||
| + | |- | ||
| + | | [[Oxygen difluoride|OF<sub>2</sub>]] | ||
| + | | 140.5 | ||
| + | | 103 | ||
| + | | | ||
| + | | [[Oxygen difluoride|F<sub>2</sub>O]] | ||
| + | | 140.5 | ||
| + | | 103 | ||
| + | |- | ||
| + | | [[Hypofluorous acid|HOF]] | ||
| + | | 144.2 (O–F)<br/>96.4 (O–H) | ||
| + | | 97 | ||
| + | | | ||
| + | | [[Dichlorine monoxide|Cl<sub>2</sub>O]] | ||
| + | | 170.0 | ||
| + | | 110.9 | ||
| + | |- | ||
| + | | [[Water|H<sub>2</sub>O]] | ||
| + | | 95.7 | ||
| + | | 104.5 | ||
| + | | | ||
| + | | [[Dibromine monoxide|Br<sub>2</sub>O]] | ||
| + | | 184.3 | ||
| + | | 112.2 | ||
| + | |- | ||
| + | |} | ||
==Notes and references== | ==Notes and references== | ||
| Line 35: | Line 81: | ||
==External links== | ==External links== | ||
{{wikipedia|Oxygen difluoride}} | {{wikipedia|Oxygen difluoride}} | ||
| + | *[http://www.webelements.com/compounds/oxygen/oxygen_difluoride.html WebElements] | ||
[[Category:Oxygen compounds]] | [[Category:Oxygen compounds]] | ||
[[Category:Fluorides]] | [[Category:Fluorides]] | ||
| + | [[Category:Fluorinating agents]] | ||
{{CC-BY-3.0}} | {{CC-BY-3.0}} | ||
Latest revision as of 11:39, 1 January 2011
| Oxygen difluoride | |
|---|---|
| IUPAC name | Oxygen difluoride |
| Other names | Difluorine monoxide Difluorooxidane Difluoridooxygen |
| Identifiers | |
| InChI | InChI=1/F2O/c1-3-2 |
| InChIKey | UJMWVICAENGCRF-UHFFFAOYAI |
| Standard InChI | InChI=1S/F2O/c1-3-2 |
| Standard InChIKey | UJMWVICAENGCRF-UHFFFAOYSA-N |
| CAS number | [] |
| EC number | |
| ChemSpider | |
| Properties[1][2][3] | |
| Chemical formula | OF2 |
| Molar mass | 55.996 g mol−1 |
| Appearance | colourless gas |
| Density | 1.90 g cm−3 (liquid, −223.8 °C) |
| Melting point |
−223.8 °C (49.4 K) |
| Boiling point |
−145.3 °C (127.9 K) |
| Thermochemistry[4] | |
| Std enthalpy of formation ΔfH |
+24.52 kJ mol−1 |
| Standard molar entropy S |
247.46 J K−1 mol−1 |
| Related compounds | |
| Other fluorides of oxygen | Dioxygen difluoride |
| Other compounds | Dichlorine monoxide Dibromine monoxide |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
Oxygen difluoride, OF2, sometimes known as difluorine monoxide,[note 1] is the most stable of the binary compounds of oxygen and fluorine.[1][7] It was discovered as a byproduct of fluorine production using Moissan cells (electrolysis of HF/KF) due to small amounts of water in the electrolyte.[8] A more satisfactory method of preparation is the reaction of fluorine with 2% aqueous sodium hydroxide solution followed by fractional distillation of the gas produced.[9][10][11]
Structure
Oxygen difluoride has a bent C2v structure as expected by VSEPR theory. The oxygen–fluorine bond length is 140.5 pm and the bond angle at oxygen is 103°, consistent with single bonding and sp3 hybridization at oxygen.[1][7]
| r(O–X)/pm | X–O–X/° | r(O–X)/pm | X–O–X/° | |||
|---|---|---|---|---|---|---|
| OF2 | 140.5 | 103 | F2O | 140.5 | 103 | |
| HOF | 144.2 (O–F) 96.4 (O–H) |
97 | Cl2O | 170.0 | 110.9 | |
| H2O | 95.7 | 104.5 | Br2O | 184.3 | 112.2 |
Notes and references
Notes
- ↑ Fluorine is more electronegative than oxygen, both on the normal numerical scales[5] and on the conventional series used in inorganic nomenclature,[6] so OF2 is usually considered a fluoride of oxygen and not an oxide of fluorine. However, other X2O compounds (X = Cl, Br) are considered to be halogen oxides, and so F2O is sometimes considered to be a member of this series, despite its somewhat different chemistry.[7]
References
- ↑ 1.0 1.1 1.2 Greenwood, Norman N.; Earnshaw, A. Chemistry of the Elements; Pergamon: Oxford, 1984; pp 748–49. ISBN 0-08-022057-6.
- ↑ CRC Handbook of Chemistry and Physics, 62nd ed.; Weast, Robert C., Ed.; CRC Press: Boca Raton, FL, 1981; p B-126. ISBN 0-8493-0462-8.
- ↑ Streng, Alex G. Miscibility and Compatibility of Some Liquid and Solidified Gases at Low Temperature. J. Chem. Eng. Data 1971, 16 (3), 357–59. DOI: 10.1021/je60050a024.
- ↑ Difluorine monoxide. In NIST Chemistry WebBook; National Institute for Standards and Technology, <http://webbook.nist.gov/cgi/inchi/InChI%3D1S/F2O/c1-3-2>. (accessed 31 December 2010).
- ↑ Allred, A. L. Electronegativity values from thermochemical data. J. Inorg. Nucl. Chem. 1961, 17 (3–4), 215–21. DOI: 10.1016/0022-1902(61)80142-5.
- ↑ Nomenclature of Inorganic Chemistry; IUPAC Recommendations 2005; Royal Society of Chemistry: Cambridge, 2005; p 260. ISBN 0-85404-438-8, <http://www.iupac.org/publications/books/rbook/Red_Book_2005.pdf>.
- ↑ 7.0 7.1 7.2 Cotton, F. Albert; Wilkinson, Geoffrey Advanced Inorganic Chemistry, 5th ed.; Wiley-Interscience: New York, 1988; pp 454–56. ISBN 0-471-84997-9.
- ↑ Lebeau, P.; Damiens, A. Sur l'existence d'un composé oxygéné du fluor. C. R. Hebd. Acad. Sci. Paris 1927, 185, 652–54, <http://gallica.bnf.fr/ark:/12148/bpt6k31384/f652.image>.
- ↑ Lebeau, P.; Damiens, A. Sur un nouveau mode de préparation du fluorure d'oxygène. C. R. Hebd. Acad. Sci. Paris 1929, 188, 1253–55, <http://gallica.bnf.fr/ark:/12148/bpt6k31417/f1253.image>.
- ↑ Yost, D. M. Oxygen Fluoride. Inorg. Synth. 1939, 1, 109–11.
- ↑ Appelman, Evan H.; Jache, Albert W. Concerning the mechanism of formation of oxygen difluoride. J. Am. Chem. Soc. 1987, 109 (6), 1754–57. DOI: 10.1021/ja00240a026.
External links
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See also the corresponding article on Wikipedia. |
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