Tetrachloroaluminic acid Aluminum chloride

An elegant entry into the phosphonic acid series is provided by the reaction of phosphorus trichloride with alkyl chlorides in the presence of anhydrous aluminum chloride, as discovered by American189 and British investigators.190> 191 The alkyl chloride is added in up to 25% excess, with exclusion of moisture and if necessary with cooling, to an equimolar mixture of phosphorus trichloride and aluminum chloride the alkyltrichlorophosphonium tetrachloroaluminate, generally in crystalline form, is obtained and is then dissolved in methylene dichloride and hydrolysed cautiously to the phosphonic dichloride ... 

Tetrachloroaluminic acid s. Aluminum chloride/ hydrogen chloride Tetrachloro-o-benzoquinone s. o Chloranil... 

A somewhat less obvious example of a Lewis acid—base reaction is the reaction of chloromethane with aluminum chloride to give a tetrachloroaluminate ion and a methyl carbocation, a potent Lewis acid. We will discuss this reaction in Chapter 13. 

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