The Construction of Open Gd^III Metal–Organic Frameworks Based on Methanetriacetic Acid: New Objects with an Old Ligand

Abstract

The preparation, X‐ray crystallography and magnetic investigation of the first examples of methanetriacetate (mta)‐containing lanthanide(III) complexes of formulae [Gd(mta)(H2O)3]n⋅4 n H2O (1) [Gd(mta)(H2O)3]n⋅2 n H2O (2) and [Gd2(mta)2(H2O)2]n⋅2 n H2O (3) are described herein. This tripodal ligand promotes the formation of 63 networks; thus 1 consists of a honeycomb structure, whereas in 2 two of these layers are condensed to form a rare five‐connected two‐dimensional (4862) network. Compound 3 can be seen as an aggregation of 63 layers leading to a three‐dimensional (6,6)‐connected binodal (41263)(4966)‐nia net, in which the gadolinium(III) ions and the mta ligands act as octahedral and as trigonal prismatic nodes, respectively. The magnetic properties of 1–3 were investigated in the temperature range 1.9–300 K. A close fit to the Curie law (1) and weak either antiferro‐ [J=−0.0063(1) cm−1 (2)] or ferromagnetic [J=+0.0264(6) cm−1 (3)] interactions between the GdIII ions are observed; the different exchange pathways involved [extended tris‐bidentate mta (1) and μ‐O(1);κ2O(1),O(2) (2 and 3) plus single syn–syn carboxylate‐mta (3)] accounting for these magnetic features. The nature and magnitude of the magnetic interactions, between the GdIII ions in 1–3, agree with the small amount of data existing in the literature for these kind of bridges.

Three new europium(III) methanetriacetate metal-organic frameworks: the influence of synthesis on the product topology

“…The first Eu III -containing methanetriacetate compounds have been synthesized, through gel [for (I)] and hydrothermal methods [for (II) and (III)]. Two of them, (I) and (II), are isomorphous with two Gd III compounds reported previously (Cañ adillas-Delgado et al, 2010), where the main differences arise from the lanthanide contraction. Compound (III) represents a new polymorph.…”

“…Its structure consists of [Eu(H 2 O)] 3+ units and six-connecting mta 3À ligands acting as octahedral and trigonal prismatic nodes, respectively, which result in a three-dimensional network showing the NiAs topology [a (6,6)-connected binodal nia-net (Blatov, 2006), with a (4 12 6 3 )(4 9 6 6 ) Schlä fli symbol], which is quite rare among MOF architectures (Figs. 3 and 4; Delgado-Friedrichs et al, 2006;Chen et al, 2012;Bai et al, 2008;Cañ adillas-Delgado et al, 2010;Chae et al, 2001;Jia et al, 2012). The structure contains chains of oxo-and syn-syn carboxylate-bridged Eu III ions running along the b axis, which are interconnected through the mta 3À ligands to yield the full three-dimensional framework.…”

“…In this paper we report three new metal-organic frameworks containing Eu III Methanetriacetic acid (H 3 mta) was prepared and characterized following reported methods (Baumeister et al, 2002;Gupta et al, 1987;Cañ adillas-Delgado et al, 2010). The other reagents and solvents were purchased from commercial sources and used as received.…”

Synthesis, structure, and magnetism of a ytterbium coordination polymer with 5-sulfonyl-1,2,4-benzenetricarboxylate and oxalate

“…Combination of the characteristics of organic and inorganic components offers an opportunity to incorporate useful properties within a single composite, providing access to multifunctional materials. Lanthanides attract attention for unique physical properties arising from 4f electrons [6][7][8][9]. High coordination number and flexible coordination geometry of lanthanide ions make it difficult to control preparation of lanthanide compounds.…”

Highly porous and robust ionic MOFs with nia topology constructed by connecting an octahedral ligand and a trigonal prismatic metal cluster

“…8 Notably, binodal NiAs-type (nia) topology with both octahedral and trigonal prismatic building blocks is rarely observed in MOFs. [9][10][11][12][13][14] Yaghi et al have reported that a nia-type MOF can be generated by connecting a trigonal prismatic six-node ligand with an octahedral Zn 4 O cluster. 14 Conversely, we think that a nia topology can also be formed by connecting a trigonal prismatic IBB with an octahedral OBB.…”