Chromium compounds, cell preparation

The synthesis of anhydrous metal halides is often a complex process. In thermal dehydration reactions complete removal of water is often complicated by decomposition of the compound. The reactions of metals with gaseous hydrogen halides or with halogens usually takes place at high temperatures and requires apparatus that may not be avaUable routinely. For example, CrBra can be obtained by the action of Br2 on chromium metal at a temperature of 750 °C.53 An alternative method has been proposed for the preparation of this compound that involves the anodic dissolution of chromium in the presence of bromine with a platinum cadiode immersed in benzene connected by a salt bridge to a chromium anode immersed in MeOH/Br2. The electrolytic cell is represented by Eq. 7.7 ... 

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