Poly[[penta-aqua-(μ(4)-pyridine-2,4,6-tri-carboxyl-ato)(μ(3)-pyridine-2,4,6-tri-carboxyl-ato)diterbium(III)] mono-hydrate].

The three-dimensional title coordination polymer, {[Tb(2)(C(8)H(2)NO(6))(2)(H(2)O)(5)]·H(2)O}(n), was hydro-thermally synthesized by reacting the corresponding rare-earth salt with pyridine-2,4,6-tricarb-oxy-lic acid (H(3)ptc). There are two independent Tb(III) atoms in the structure, one of which is nine-coordinated, forming a monocapped NO(8) square-anti-prism and the other is eight-coordinated exhibiting a 4,4-bicapped NO(7) trigonal-prismatic environment. The complex units are inter-connected through the ptc(3-) anions acting in different coordination modes, resulting in a three-dimensional coordin-ation polymer. The crystal structure features extensive O-H⋯O hydrogen bonds.