Dioxouranium(VI) complexes with N2O2 chelating thiosemicarbazones [UO2L(R-OH)]

Abstract

Three alkylated thiosemicarbazones (1-3) substituted on sulfur were synthesized using 5-bromosalicylaldehyde as starting material. The template reactions of the S-alkyl-thiosemicarbazones in the presence of dioxouranium(VI) were investigated. Six dioxouranium(VI) (1a-3b) complexes were synthesized. Propyl or allyl alcohol used as second ligand completed the seventh coordination site of UO22+. The synthesized thiosemicarbazones and template complexes were characterized by elemental analysis, UV-visible, FTIR, and H-1 NMR. The structure of the dioxouranium(VI) complex, [UO2L(allylalcohol)], was studied by single-crystal diffraction. The uranium is seven-coordinate in a pentagonal-bipyramidal arrangement with two oxo groups occupying the apical positions.