Crystal structure of two new molecular adducts of uranyl nitrate with 2,2′-6,2″-terpyridine

Abstract

The crystal structures of two uranyl nitrate complexes with 2,2′-6,2″-terpyridine (Trpy), [(UO (Trpy)-[(UO2)2(Trpy)2(OH)2][UO2(NO3)2(OH)2] · 2CH3OH (I) and [(UO2)2(Trpy)2(OH)2]2[UO2(NO3)3(H2O)](NO3)3 · 3H2O (II), were studied. Compound I consists of the centrosymmetric dimeric cations [(UO2)2(Trpy)2(OH)2]2+, the anions [UO2(NO3)2(OH)2]2−, and solvation methanol molecules. Complex II consists of dimeric cations [(UO2)2(Trpy)2(OH)2]2+, the complex anions [UO2(NO3)3(H2O)]−, nitrate anions, and water molecules of crystallization. The uranium atom in the [UO2(NO3)3(H2O)]− anion in II has an unusual coordination polyhedron representing a hexagonal bipyramid in which one oxygen atom in the equatorial plane is replaced by two atoms equidistant from this plane.