TRANSITION-METAL COMPLEXES WITH THIOSEMICARBAZIDE-BASED LIGANDS .31. DIOXOURANIUM(VI) COMPLEXES WITH )-N(4)-SALICYLIDENE-S-ALKYL-ISOTHIO-SEMICARBAZIDES AND E-N(4)-SALICYLIDENE-S-ALKYL-ISOTHIO-SEMICARBAZIDES

Solvate complexes of UO22+ and N(1), 4)-bis(salicylidene)-S-methylisot hiosemicarbazone, (H2Me-L-1), of general formula [UO2(Me-L-1)(S)] (S = H2O, MeOH, EtOH, Py, DMF and DMSO) were synthesized. The methanolic U O22+ adducts of ene-N(4)-salicylidene-S-alkylisothiosemicarbazone, (H2 R-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.