Structure and spectroscopy of uranyl salicylaldiminate complexes

The synthesis of uranyl complexes coordinated to tridentate, monoanionic salicylaldiminate (Schiff base) ligands was achieved by the reaction of UO2Cl2(THF)(3), 1, with one equivalent of the corresponding sodium salicylaldiminate salts affording [(C9H6N)N=C(H)(C6H2Bu2O)-Bu-t]UO2Cl(THF), 2, [(NC5H4)N=C(H)(C6H2Bu2O)-Bu-t]UO2Cl(THF), 3, and [(C6H4SCH3)N=C(H)(C6H2Bu2O)-Bu-t]UO2Cl(THF), 4. These are uncommon examples of uranyl complexes with a monoanionic ancillary ligand to stabilize the coordination sphere and one chloride ligand. Compounds 2-4 have been characterized by H-1 and C-13 NMR spectroscopy as well as IR and UV-Vis spectroscopy and their structures determined by X-ray crystallography.