A family of lanthanide-containing molecular open frameworks with high porosity: [Ln(abdc)(Habdc), nH2O]∞ with Ln = La-Eu and 8 ≤ n ≤ 11

Reactions in water between the di-sodium salt of amino terepthalic acid (C8H3NO4Na2) and a lanthanide chloride lead to a family of 3D- coordination polymers with general chemical formula [Ln(C8H3NO4)(C8H4NO4), O](infinity) where Ln = La- Eu (except Pm) and 8 <= n <= 11. All these compounds are isostructural. High quality single crystals of [Ln(C8H3NO4)(C8H4NO4), nH(2)O] 1 with Ln = La-Sm (except Pm) and 8 <= n <= 11 have been obtained by slow diffusion in agar- agar gels. The crystal structure has been solved for the Nd- containing compound. This compound crystallizes in the cubic system, space group Ia-3 (no. 206) with a = 26.8056(5) angstrom. The crystal structure can be described as the juxtaposition of large channels with square cross- section. The channels are filled by highly disordered crystallization water molecules. The dehydration of the compounds by freeze- drying is possible and most of the crystallization water molecules can be removed without destruction of the molecular skeleton. The partially dehydrated compounds have general chemical formula [Ln(abdc)(Habdc), 2H(2)O](infinity) with Ln = La- Eu except Pm. The porosity of the Nd-containing compound has been estimated by computational methods to 2170 m(2) g(-1). This dehydrated compound reversibly binds water when exposed to wet atmosphere restoring the initial hydrated phase. (C) 2011 Elsevier B.V. All rights reserved.