TRANSITION METAL COMPLEXES WITH THIOSEMICARBAZIDE-BASED LIGANDS 31. Dioxouranium(VI) complexes with N(1),N(4)-bis(salicyfidene)- and N(1)-benzoylisopropyfidene- N(4)-saficylidene-S-alkyl-isothio-semicarbazides

Solvate complexes of UO22+ and N(1), N(4)-bis(salicylidene)-S-methylisothiosemicarbazone, (H2Me-L-1), of general formula [UO2(Me-L-1)(S)] (S = H2O, MeOH, EtOH, Py, DMF and DMSO) were synthesized. The methanolic UO22+ adducts of N(1)-benzoylisopropylidene-N(4)-salicylidene-S-alkylisothiosemicarbazone, (H2R-L-2, R = Me, Pr-II) of general formula [UO2(R-L-2). MeOH], were also prepared. Thermal decomposition of the complexes was investigated in air and argon. The complexes decompose to alpha-U3O8 in air, while in argon the decomposition is not completed up to 1000 K. The temperature and the mechanism of decomposition of the complexes are a function of the solvent belonging to the inner coordination sphere.