Actinide interactions with microbial chelators: the dioxobis[pyridine-2,6-bis(monothiocarboxylato)]uranium(VI) ion

The title complex, bis(tetraphenylphosphonium) dioxobis(pyridine-2,6-dicarb othioato-O,N,O')uranium(VI), (C24H20P)(2)-[UO2(C7H3NO2S2)(2)], was prepared by reacting two equivalents of pyridine-2,6-bis(monothiocarboxylate) (pdtc ) with uranyl nitrate. The geometry of the eight-coordinate U atom is hexag onal bipyramidal, with the uranyl O atoms in apical positions. This is the first reported complex in which this ligand binds a metal through the O and not the S atoms. Principal bond lengths include uranyl lengths of 1.774 (2 ) Angstrom, U-O distances of 2.434 (2) and 2.447 (3) Angstrom, and two U-N distances of 2.647 (3) Angstrom. The anion lies on an inversion centre.