Synthesis, structure, and thermolysis of compounds of uranyl acetate with some amides

Abstract

The present investigation was devoted to studying the changes in the structure of the intial uranyl carboxylate UO/sub 2/(CH/sub 3/COO)/sub 2/.2H/sub 2/O connected with the introduction of neutral nitrogen-containing ligands into the coordination sphere of the uranyl group, and also the nature of the coordination and the composition of the additional ligands on the course of the thermal decomposition of the complex. Complex compounds of uranyl acetate with dimethylacetamide and urea that have been described previously have been synthesized. On the basis of x-ray structural results the following formulas have been established for the compounds obtained: (UO/sub 2/(CH/sub 3/COO)/sub 2/.DMAA)/sub 2/ and (UO/sub 2/(CH/sub 3/COO)Ur/sub 3/)(UO/sub 2/(CH/sub 3/COO)/sub 3/). As the result of thermal analysis (polythermal and isothermal conditions) of bisdiacetato(dimethylacetamide)uranyl (VI) and the acetatoureauranyl(VI) triacetatodioxouranate(VI) it has been shown that the course of the thermal decomposition of the amide complexes of uranyl acetate, and also the composition of the oxide formed in this process are determined by the presence of the H atoms in the amide grouping which participate in the formation of hydrogen bonds in the compounds and lead to an increased mobility of the nitrogen atoms.