Using a Halogenated Silica Surface

Modification Using a Halogenated Silica Surface. Silica gel is heated in 2 m HC1, filtered off, and washed with water the dried silica gel is then reacted with pure thionyl chloride. After removal of the excess of thionyl chloride and byproducts (S02 and HC1) under vacuum, chlorinated silica gel (=SiCl) is obtained. This is unstable in water and alcohol. The chlorinated silica gel can then be alkylated by one of a number of different reactions  

The chlorinated silica gel suspended in diethyl ether, dimethyl sulfoxide, or dioxane will also react with diamine or amino compounds. After being washed in an excess of amine and HC1, and then dried under vacuum, the final stationary phase materials are obtained  

Further modification of diamino bonded products with halogenated compounds can lead to a variety of stationary phase materials  

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