Synthesis, Structure, and Mössbauer Study of [Fe(H2O)2(C9O6H4)]·H2O:  A Two-Dimensional Iron(II) Trimellitate (MIL-67)

• Published in: Inorganic chemistry 2003-09, Vol.42 (18), p.5669-5674
• Main Authors: Riou-Cavellec, Myriam, Lesaint, Cédric, Noguès, Marc, Grenèche, Jean-Marc, Férey, Gérard
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic020715y

The two-dimensional (2D) iron trimellitate [Fe(H2O)2(C9O6H4)]·H2O, labeled MIL-67, has been obtained under hydrothermal conditions (473 K, 48 h). In the 2D structure of MIL-67, the Fe2+ ions display two different octahedral environments:  [FeO4(H2O)2] and [FeO2(H2O)4]. These octahedra share an apical water molecule to form infinite chains. The chains are linked by partly deprotonated C9O6H4 2- anions to give hybrid organic−inorganic layers; the remaining acidic−CO2H group is dangling in the interlayer space. Below 8(1) K, MIL-67 displays a canted antiferromagnetic behavior, according to analyses via magnetic measurements and Mössbauer spectroscopy. Crystal data for MIL-67 are as follows: triclinic; space group P1̄ (No. 2), with a = 6.9671(2) Å, b = 7.3089(3) Å, c = 12.5097(3) Å, α = 78.758(1)°, β = 89.542(2)°, and γ = 65.197(1)°; volume V = 565.21(3) Å3; and Z = 2.