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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 |
EC Number |
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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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Sodium naphthalene is an organic salt with the chemical formula Na+[ C10 H8−. 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]
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]
With 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.
The anion is strongly basic, and a typical degradation pathway involves reaction with water and related protic sources such as alcohols. These reactions afford dihydronaphthalene:
Alkali metal salts of the naphthalene radical anion are used to prepare complexes of naphthalene. [7]