Thermolysis of Urea Complexes of Uranyl Nitrate

Abstract

Quantitative parameters of thermolysis of uranyl nitrate urea complexes, [UO2(NO3)2{(NH2)2·CO}2], [UO2(H2O){(NH2)2CO}4](NO3)2, and [UO2(H2O){(NH2)2CO}5](NO3)2 at 175, 200, and 225°C were measured. Thermolysis of [UO2(NO3)2{(NH2)2CO}2] at 200°C affords the biuret complex of uranyl nitrate in a 90% yield. The urea ligands in the hydrated complexes completely transform into biuret at 175°C. Thermolysis of [UO2(H2O){(NH2)2CO}5](NO3)2 yields the biuret-cyanurate complexes of uranyl nitrate. The features of thermolysis of the uranyl nitrate complexes originate from the chemical transformations of urea at elevated temperatures.