Tetralithiomethane

Tetralithiomethane, also known as tetralithium carbide, is an organolithium compound with the formula CLi₄. It is an extremely pyrophoric red solid and is the lithium analog of methane.^[2]

Tetralithiomethane

Names
IUPAC name Tetralithiomethane
Other names Carbon tetralithium Lithium carbide Tetralithium carbide
Identifiers
CAS Number	38827-79-1
3D model (JSmol)	Interactive image
InChI InChI=1S/C.4Li Key: SOAIVWSMVGHHPJ-UHFFFAOYSA-N
SMILES [Li]C([Li])([Li])[Li]
Properties
Chemical formula	CLi4
Molar mass	39.77 g·mol−1
Appearance	Red solid
Melting point	225 °C (437 °F; 498 K)[1] (decomposes)
Solubility in water	Hydrolysis
Solubility	Soluble in cyclohexane
Hazards
GHS labelling:
Pictograms
Related compounds
Related compounds	Methane Methyllithium Lithium acetylide Lithium nitride Lithium phosphide Lithium arsenide Lithium oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Production

Its main route of production is by the lithiation of tetrakis(chloromercurio)methane (C(HgCl)₄) by tert-butyllithium. It can also be produced by the reaction of lithium metal and carbon tetrachloride at 900 °C:^[2][3]

8 Li + CCl₄ → CLi₄ + 4 LiCl

However, this method also produces byproducts, such as lithium carbide.

Reactions

Tetralithiomethane is an extremely strong base, and hydrolyzes vigorously in contact with water producing methane gas and lithium hydroxide:^[2]

CLi₄ + 4 H₂O → CH₄ + 4 LiOH

Deuterated methane CD₄ can also be produced by reacting heavy water with tetralithiomethane.

CLi₄ + 4 D₂O → CD₄ + 4 LiOD

When tetralithiomethane is heated to 225 °C, it decomposes to lithium carbide and lithium metal.^[1][2]

Due to the known affinity of lithium ions Li⁺ for hydrogen molecules H₂ and therefore potential applications in hydrogen storage materials, tetralithiomethane has been studied computationally for its aggregation, H₂ affinity, and binding to various graphene-type surfaces.^[4]