Crystal structure of bis-(acetato-κ,')di-aqua-[1-(pyridin-2-yl-methyl-idene-κ)-2-(pyridin-2-yl-κ)hydrazine-κ]terbium(III) nitrate monohydrate.

In the title compound, [Tb(CHO)(CHN)(HO)]NO·HO, the Tb ion is nine-coordinated in a distorted tricapped trigonal-prismatic geometry by the three N atoms of the tridentate 1-(pyridin-2-yl-methyl-idene)-2-(pyridin-2-yl)hydrazine ligand, four carboxyl-ate O atoms of two chelating acetate groups and two O atoms of the coordinating water mol-ecules. The organic hydrazine ligand is disordered over two orientations with a refined occupancy ratio of 0.52 (3):0.48 (3). All bond lengths in the coordination environment of the Tb ion are slightly larger than those observed in the isostructural Y and Er complexes. In the crystal, the complex cations are linked by pairs of O-H⋯O hydrogen bonds into dimers. These dimers, nitrate anions and non-coordinating water mol-ecules are joined by O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional structure.