Sodium naphthalenide

Sodium naphthalenide

Names
Preferred IUPAC name Sodium naphthalenide
Systematic IUPAC name Sodium naphthalen-1-ide
Identifiers
ChemSpider	10004279
EC Number	222-460-3
Jmol interactive 3D	Image
PubChem	11829632
InChI InChI=1S/C10H8.Na/c1-2-6-10-8-4-3-7-9(10)5-1;/h1-8H;/q-1;+1 Key: NCVIXNVCXNGGBW-UHFFFAOYSA-N InChI=1/C10H8.Na/c1-2-6-10-8-4-3-7-9(10)5-1;/h1-8H;/q-1;+1 Key: NCVIXNVCXNGGBW-UHFFFAOYAJ
SMILES c1ccc2=C[CH][CH-]C=c2c1.[Na+]
Properties
Chemical formula	C10H8Na
Molar mass	151.16 g·mol^−1
Related compounds
Other anions	Sodium cyclopentadienide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Sodium naphthalenide, also known as sodium naphthalide, is an organic salt with the formula Na⁺C₁₀H₈⁻. In the research laboratory, it is used as a reductant in the synthesis of organic, organometallic, and inorganic chemistry. It has not been isolated as a solid, but it is usually prepared fresh before use.^[1]

Preparation and properties

The alkali metal naphthalenides 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, with a reduction potential near -2.5 V vs NHE. Its deep green color arises from absorptions centered at 463, 735 nm.^[1]

The anion is strongly basic, and a typical degradation pathway involves reaction with water and related protic sources. These reactions afford dihydronaphthalene:

2 NaC₁₀H₈ + 2 H₂O → C₁₀H₁₀ + C₁₀H₈ + 2 NaOH

Related reagents

For some synthetic operations, sodium naphthalenide is excessively reducing (too negative), in which case milder reductants are selected. Larger rings give milder reductants. Sodium acenaphthenide is milder by about 0.75 V.

The corresponding lithium salt, lithium naphthalenide, is also known.

A solution of lithium naphthalenide, a related compound, in tetrahydrofuran

References

1. N. G. Connelly and W. E. Geiger, "Chemical Redox Agents for Organometallic Chemistry", Chem. Rev. 1996, 96, 877-910. doi:10.1021/cr940053x
2. Corey, E. J.; Gross, Andrew W. (1993). "tert-Butyl-tert-octylamine". Org. Synth.; Coll. Vol. 8, p. 93
3. Cotton, F. Albert; Wilkinson, Geoffrey (1988), Advanced Inorganic Chemistry (5th ed.), New York: Wiley-Interscience, p. 139, ISBN 0-471-84997-9
4. Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. p. 111. ISBN 0-08-022057-6.