Synthesis and crystal structures of new complexes of Np(V) glycolate with 2,2 '-bipyridine, [NpO2(C10H8N2)(OOC2H2OH)]center dot 1.5H(2)O and [NpO2(C10H8N2)(OOC2H2OH)]center dot 2.5H(2)O

摘要

Single crystals were prepared, and the structures of two complexes of Np(V) glycolate with 2,2'-bipyridine of the compositions [NPO2(C10H8N2)(OOC2H2OH)]center dot 1.5H(2)O(I) and [NpO2(C10H8N2)(OOC2H2OH)center dot 2.5H(2)O (II) were studied. The structures of the compounds are based on neptunyl-glycolate chains in which the glycolate anion manifests its complexation ability in different manner. In structure, the bidentate-bridging anion links the adjacent NpO2+ cations through the oxygen atoms of the carboxylate group. The neptunyl-glycolate chains of I exhibits the mutual coordination of the NpO2+ cations acting toward each other simultaneously as ligands and coordinating centers. In compound II, the glycolate anion is bidentately coordinated to one neptunium atom to form a planar five-membered metallocycle [NpOCCO]. The O atom external with respect to the metallocycle is in the coordination environment of the adjacent neptunyl. The nitrogen-containing molecular ligand Bipy is included into the coordination environment of Np. The coordination polyhedron of the Np atoms in both structures is a pentagonal bipyramid in which the average Np-N bond length is 2.666 angstrom (1) and 2.596 angstrom (II).