Hydrothermal synthesis of the first iron arsenate-oxalate [C4N2H12]2[Fe4(HAsO 4)6(C2O4)2], possessing open architecture

The hydrothermal synthesis and structural characterization of the first iron arsenate-oxalate [C4N2H12]2[Fe4(HAsO 4)6(C2O4)2], I, with open-framework structure has been described. Crystal data for I: triclinic, space group P(-1) (no. 2), a = 11.1066(2), b = 12.9842(1), c = 13.4294(1) Ã?, α = 111.345(1), β = 93.688(1), γ = 93.879(1)°, V = 1706.33(4) Ã?3 Z = 2, Ï?calc = 2.755 gcm-3, μ(MoKα) = 7.567 mm-1, R1 = 0.0441 and wR2 = 0.113 for 3861 reflections with I > 2Ï? (I). The framework structure of I consists of neutral inorganic sheets formed by the linkages between strictly alternating FeO6 octahedra and AsO4 tetrahedra cross-linked by the oxalate units forming an anionic three-dimensional network with channels. The charge compensating doubly protonated piperazine molecules occupy these channels and interact with the framework through strong hydrogen bonds. The compound shows strong anti-ferromagnetic interactions with TN â?¼ 40 K. © 2002 Ã?ditions scientifiques et médicales Elsevier SAS. All rights reserved.