2,2′,2′′-Nitrilo­tris­(ethyl­ammonium) tris­(pyridine-2,6-di­carboxyl­ato-κ³O,N,O′)­terbate(III) hexahydrate

The asymmetric unit of the title compound, (C₆H₂₁N₄)[Tb(C₇H₃NO₄)₃]·6H₂O, consists of a (C₆H₂₁N₄)³⁺ cation, and a [(C₇H₃NO₄)₃Tb]³⁻ anion, and six molecules of water. In the anion, three pyridine-2,6-di­carboxyl­ate ligands are coordinated to the Tb^III atom via the N atom of the pyridine ring and two O atoms of different carboxyl­ate groups. The coordination polyhedron around Tb may be described as a pseudo-tricapped trigonal prism. The crystal packing is stabilized by electrostatic interactions and intermolecular hydrogen bonds involving the cation, anion and water mol­ecules.