Curium halides

Curium halides. Like americium, curium forms binary halides in the oxidation states of III and... 

When curium is heated with fluorine at 400°C, the product is CmF4, a tetravalent curium compound. However, heating with other halogens yields trivalent halides, CmXa. Similarly, when heated with hydrogen chloride gas at 500°C, the product is curium(lll) chloride, CmCls. 

Many compounds of curium are known. They include the oxides, Cm02 and Cm203, fluorides CmF4 and CmFs, other halides, CmXa hydroxide, Cm(OH)3, and oxalate Cm2(C204)3. The oxide, hydroxide, fluoride, and oxalate salts are insoluble in water and may be obtained by precipitation reactions. 

The solubility properties of curium(111) compounds are in every way similar to those of Ihe other tripositive Actinide elements and the tnpositive Lanthanide elements. Thus the fluoride and oxalate tire insoluble in acid soluliun, while the nitrate, halides, sulfate, perchlorate, and sullide are all soluble. 

To date, the hahdes represent by far the most extensively characterized class of curium compounds (refer to Table 9.2). The complete CmXs series (X = F, Q, Br, I), as well as CmF4 and several complex Cm(iv) fluorides, have been prepared and studied. Several reviews deal specifically with actinide halides and for further information (especially for cross-comparisons of Cm with other actinide halides) the reader is referred to these articles [2, 3, 58, 59]. 

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