What is LiCH3?
Methyllithium, abbreviated as LiCH3, is a primary organolithium reagent used in organic synthesis and organometallic chemistry. It has an oligomeric shape both in a solid and liquid state. It is highly reactive and is used as the artificial counterpart of the methyl anion synthon.
Table of Content
- LiCH3 Acid or Base
- Structure of LiCH3
- Synthesis of LiCH3
- Reaction of LiCH3
- Frequently Asked Questions – FAQs
LiCH3 Acid or Base
LiCH3 is a strong base. It interacts with an electron-deficient species and forms a covalent bond with it. In LiCH3, the carbon atom acquires a partial negative charge, due to which it has an affinity for electron-deficient species.
It is a primary organolithium reagent used in organic synthesis and organometallic chemistry. It is highly reactive and is used as the artificial counterpart of the methyl anion synthon.
Structure of LiCH3
LiCH3 exists in a distorted cubane-type cluster in its solid form, containing lithium and carbon atoms at alternate corners. It exists in cubic body-centred packing of (LiCH3 )4 units. In LiCH3, the Li-Li distance is equivalent to 2.68 Å. In contrast, the C-Li distance is equal to 2.31 Å. The carbon atom is linked to three hydrogen atoms and three lithium atoms. It has inter-cluster agostic interactions, due to which it is non-volatile and insoluble in water.
Synthesis of LiCH3
LiCH3 can be synthesised by reacting methyl chloride with a suspension of lithium in diethyl ether.
2 Li + CH3Cl → LiCH3 + LiCl
The above reaction can also occur with methyl bromide, but it is less preferred as it forms a complex with methyl lithium (LiCH3).
Methyl lithium (LiCH3) is treated with dioxane to precipitate lithium bromide dioxane, removed by filtration.
Reaction of LiCH3
Reaction with Carbon dioxide
LiCH3 reacts with carbon dioxide to form lithium acetate.
LiCH3 + CO2 → CH3COO−Li+
Reaction with Non-Metal Halides
LiCH3 is used to convert non-metal halides to methyl compounds.
PCl3 + 3 LiCH3 → P(CH3)3 + 3 LiCl
Reaction with Metal Halides
LiCH3 reacts with metal halides to form transition metal methyl compounds.
6 LiCH3 + ZrCl4 → Li2Zr(CH3)6 + 4 LiCl
Frequently Asked Questions on LiCH3 Acid or Base
What is LiCH3?
Methyllithium, abbreviated as LiCH3, is a primary organolithium reagent used in organic synthesis and organometallic chemistry. It has an oligomeric shape both in a solid and liquid state. It is highly reactive and is used as the artificial counterpart of the methyl anion synthon.
Is LiCH3 an acid or a base?
LiCH3 is a strong base. It interacts with an electron-deficient species and forms a covalent bond with it. In LiCH3, the carbon atom acquires a partial negative charge, due to which it has an affinity for electron-deficient species.
Explain the structure of LiCH3?
LiCH3 exists in a distorted cubane-type cluster in its solid form, containing lithium and carbon atoms at alternate corners. It exists in cubic body-centred packing of (LiCH3 )4 units. In LiCH3, the Li-Li distance is equivalent to 2.68 Ã…. In contrast, the C-Li distance is equal to 2.31 Ã…. The carbon atom is linked to three hydrogen atoms and three lithium atoms.
How can you synthesise LiCH3?
LiCH3 can be synthesised by reacting methyl chloride with a suspension of lithium in diethyl ether.
2 Li + CH3Cl → LiCH3 + LiCl
Why is methyl bromide not preferred for synthesising LiCH3?
Methyl bromide is not preferred for synthesising LiCH3 because it forms a complex with methyl lithium (LiCH3).
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