Sodium naphthalene is an organic salt with the chemical formula Na+[C10H8]−. In the research laboratory, it is used as a reductant in the synthesis of organic, organometallic, and inorganic chemistry. It is usually generated in situ. When isolated, it invariably crystallizes as a solvate with ligands bound to Na+.[1]
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| Names | |
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| Preferred IUPAC name
Sodium naphthalenide | |
| Systematic IUPAC name
Sodium naphthalen-1-ide | |
| Other names
sodium naphthalenide, sodium naphthalide
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| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.020.420 |
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PubChem CID
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CompTox Dashboard (EPA)
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| Properties | |
| Na+[C10H8]− | |
| Molar mass | 151.164 g·mol−1 |
| Appearance | Deep green crystals |
| Related compounds | |
Other anions
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Lithium naphthalene |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Preparation and properties
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The alkali metal naphthalene salts are prepared by stirring the metal with naphthalene in an ethereal solvent, usually as tetrahydrofuran or dimethoxyethane. The resulting salt is dark green.[2][3][4] The anion is a radical, giving a strong EPR signal near g = 2.0. Its deep green color arises from absorptions centered at 463 and 735 nm.
Several solvates of sodium naphthalenide have been characterized by X-ray crystallography. The effects are subtle, the outer pair of CH−CH bonds contract by 3 pm and the other nine C−C bonds elongate by 2–3 pm. The net effect is that reduction weakens the bonding.[5][6]
Reactions
editRedox
editWith a reduction potential near −2.5 V vs NHE, the naphthalene radical anion is a strong reducing agent.[1] It is capable of defluorinating PTFE and is commonly used for chemically etching PTFE to allow adhesion.[7]
Protonation
editThe anion is strongly basic, and a typical degradation pathway involves reaction with water and related protic sources such as alcohols. These reactions afford dihydronaphthalene:
As a ligand
editAlkali metal salts of the naphthalene radical anion are used to prepare complexes of naphthalene.[8]
Related reagents
editReferences
edit- ^ a b Connelly, Neil G.; Geiger, William E. (1996). "Chemical Redox Agents for Organometallic Chemistry". Chemical Reviews. 96 (2): 877–910. doi:10.1021/cr940053x. PMID 11848774.
- ^ Corey, E. J.; Gross, Andrew W. (1987). "tert-Butyl-tert-octylamine". Org. Syntheses. 65: 166. doi:10.15227/orgsyn.065.0166.
- ^ Cotton, F. Albert; Wilkinson, Geoffrey (1988), Advanced Inorganic Chemistry (5th ed.), New York: Wiley-Interscience, p. 139, ISBN 0-471-84997-9
- ^ Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. p. 111. ISBN 978-0-08-022057-4.
- ^ Bock, Hans; Arad, Claudia; Näther, Christian; Havlas, Zdenek (1995). "The Structures of Solvent-Separated Naphthalene and Anthracene Radical Anions". J. Chem. Soc., Chem. Commun. (23): 2393–2394. doi:10.1039/C39950002393.
- ^ Castillo, Maximiliano; Metta-Magaña, Alejandro J.; Fortier, Skye (2016). "Isolation of Gravimetrically Quantifiable Alkali Metal Arenides Using 18-Crown-6". New Journal of Chemistry. 40 (3): 1923–1926. doi:10.1039/C5NJ02841H.
- ^ López, Cristian Daniel; Cedeño-Mata, Michelle; Dominguez-Pumar, Manuel; Bermejo, Sandra (December 2020). "Surface modification of polytetrafluoroethylene thin films by non-coherent UV light and water treatment for electrowetting applications". Progress in Organic Coatings. 149: 105593. doi:10.1016/j.porgcoat.2020.105593.
- ^ Ellis, John E. (2019). "The Chatt Reaction: Conventional Routes to homoleptic Arenemetalates of d-Block Elements". Dalton Transactions. 48 (26): 9538–9563. doi:10.1039/C8DT05029E. PMID 30724934. S2CID 73436073.