メチルリチウム
メチルリチウム (2.8%エチルエーテル溶液, 約1.0mol/L) · メチルリチウム,ジエチルエーテル溶液 · メチルリチウム (約3～5%エチルエーテル溶液, 約1～2mol/L) · メチルリチウム,ジエチルエーテル溶液(BRフリー) · メチルリチウム リチウムブロミド錯体 溶液 · メチルリチウム 溶液 · メチルリチウム · メチルリチウム,シクロペンチルメチルエーテル溶液
識別子と物理属性
| CAS No. | 917-54-4 |
|---|---|
| 分子式 | CH3Li |
| 平均分子量 | 22 g/mol |
| SMILES | [CH3-].[Li+] |
| InChIKey | DVSDBMFJEQPWNO-UHFFFAOYSA-N |
| PubChem CID | 2724049 |
| ChEBI | CHEBI:51486 |
| DTXSID | DTXSID7061273 |
| 現地名 | メチルリチウム |
化学・物理的性質
| 極性表面積 | 0 |
|---|---|
| 水素結合供与体数 | 0 |
| 水素結合受容体数 | 1 |
| 回転可能結合数 | 0 |
| 重原子数 | 2 |
| 形式電荷 | 0 |
| 複雑度 | 2 |
| 融点 | 70-71℃ |
| 沸点 | 88℃ |
| 密度 | 0.85 g/mL at 20 °C |
| 蒸気密度 | 3 (vs air) |
| 引火点 | 5 °F |
| 貯蔵条件 | 2-8°C |
| 外観・状態 | 解決 |
| 比重 | 0.83 |
| 色 | 無色～黄色 |
| 爆発限界 | 1.7-36% (v/v) Information refers to the main component.) |
| 溶解度 | 水と反応する。 |
| BRN | 3587162 |
| InChI | 1S/CH3.Li/h1H3 |
| InChIKey | DVSDBMFJEQPWNO-UHFFFAOYSA-N |
| SMILES | [Li]C |
| CAS データベース | 917-54-4(CAS DataBase Reference) |
| EPAの化学物質情報 | Lithium, methyl- (917-54-4) |
化学的特性
Methyllithium is a colorless to yellowish solution, It is insoluble in hydrocarbon solvents although propyllithium and the higher homologues are miscible in hydrocarbons. Methyllithium is soluble in diethyl ether to about 6% by weight at room temperature (with or without lithium bromide) and is a little less soluble in tetrahydrofuran. Cooling of these solutions produces clear, colorless crystals of methyllithium etherate. Methyllithium is stable to about 200°C, at which temperature it disproportionates to dilithiomethane and methane.
安全性と法規制
| F | 10 |
|---|---|
| 水環境危害等級（WGK） | 2 |
| TSCA 収載状態 | TSCA listed |
| 輸送番号（UN） | UN 3399 4.3/PG 1 |
| 税関コード | 29319090 |
| 危険文句（R） | 12-15-17-22-34-66-67-65-51/53-11-36/37/38-36/38-19-40-36/37-37-14/15 |
| 安衛法 | 有機則 第二種有機溶剤等 |
| 消防法 | 危-3-I |
| 危険表示 | F+,C,N,F,Xn,Xi |
| 安全措置（S） | 16-26-36/37/39-45-43-30-60-62-61-36/37 |
| 危険等級 | 4.3Eye Dam. 1Flam. Liq. 2Pyr. Liq. 1Skin Corr. 1BWater-react 1 |
| 包装等級 | I |
| 自然発火温度 | 180°C (Information refers to the main component.) |
| 貯蔵分類 | 4.2 - Pyrophoric and self-heating hazardous materials |
用途
解説
メチルリチウム，無色の結晶性粉末．エーテルに可溶，ベンゼン，シクロヘキサンに難溶．空気中で自然発火する．付加反応性がいちじるしく，また，ハロゲンや水素とリチウムとの交換反応性がいちじるしいなど，グリニャール試薬と類似の化学的性質をもつが，その反応性はきわめて高く，有機合成化学上，重要な化合物である．森北出版「化学辞典（第2版）
使用
There are no significant industrial uses of methyllithium, but it is widely used in the laboratory in Grignard type reactions. Methyllithium is an organolithium reagent mainly used for deprotonation and as a source of methyl anion. It is a strong base and a strong nucleophile.
製法・合成法
製造方法
Methyllithium is produced industrially by the reaction of methyl chloride or methyl bromide with lithium metal dispersion in diethyl ether. The reaction with methyl chloride yields a solution of methyllithium and a precipitate of lithium chloride which may be readily separated. When methyl bromide is used, the lithium bromide byproduct remains in solution and complexes with the methyllithium. This reduces the reactivity of the methyllithium and, in certain cases, affects its usefulness. On the other hand, the less reactive complex is more stable in diethyl ether. Methyllithium produced from methyl chloride contains only about 0.3 % lithium chloride in a 5 % solution in diethyl ether. It is more reactive than the lithium bromide complex, but decomposes at the rate of 1 % of the contained methyllithium per year (that is 5.00 % solution goes to 4.95 %) at room temperature. The decomposition by ether cleavage results in methane and ethylene formation which increases the pressure in the container on long storage. Methyllithium can be prepared easily in tetrahydrofuran but it has a half-life of only about 2 days at room temperature due to solvent cleavage.