Thermal behavior of some uranyl bis-(1,3-diketonate) complexes

Thermal gravimetric (TG) and differential thermal (DTA) analyses were perfo rmed to characterize the thermal behavior and the stoichiometry of uranyl b is-1,3-diketonate complexes (R1COCR2COR3)(2) UO2 x H2O, where R-1,R-3=CH3; C2H5; C6H5; CF3; pNO(2)-C6H5; pCl-C6H4; pMe-C6H4; NH-C6H5; R-2 = H, C6H5 an d x=1; 2. Based on the data obtained, a thermal degradation mechanism for e ach complex was proposed. The final degradation product for all studied com plexes was U3O8 oxide. The temperature of the first organic fragment ruptur e including the U-O (ligand) bond was taken as criterion for the thermal st ability of the metal-oxygen donor bond in these complexes. The observed sta bility order is in good agreement with the IR determined constant force val ues, k, of the U-O (ligand) bond.