Novel 3d/4f Metal Organic Networks Containing Co^II Chiral Chains

Abstract

Novel 3d/4f heterometallic three-dimensional (3D) networks, based on CoII/GdIII cations and imidazole-4,5-dicarboxylic acid (H3IDC) and oxalate which are acting as main and auxiliary ligand, respectively, were hydro-/solvothermally synthesized using different synthetic strategies. While [Gd­(H2O)­(C2O4)­Co­(IDC)­(H2O)1.26­(CH3CH2OH)0.74]­·1.75H2O (1) was obtained in a one-pot synthesis, [Gd­(H2O)­Co­(HIDC)­(C2O4)1.5]­·2.65H2O (2) was obtained using a CoII complex precursor. Both compounds crystallize in a monoclinic system within the centrosymmetric space group C2/c. These structures are characterized by presenting an intricate covalent 3D network. A notable aspect is the fact that in these centrosymmetric structures CoII(IDC/HIDC) moieties are disposed along the networks forming alternate chiral chains, Λ and Δ. From a magnetic point of view, both (1) and (2) have antiferromagnetic interactions, but in (1) a magnetic order appears below 8 K, probably as product of uncompensated antiferromagnetic interactions produced by centers with different spin values. This ferrimagnetic behavior was verified by the hysteresis curve at 1.8 K, and by well-defined maxima, both in the in-phase and out-of-phase ac susceptibilities curves. Remarkably, this work reports efficient synthetic methods through which it is possible to generate 3d/4f networks, these being scarce in the literature.

Design and synthesis of coordination polymers with chelated units and their application in nanomaterials science

“…180 There is interest in CP with [Ca 2 L(L 0 )] n unit based on pyrazine-2-carboxylate (L) and benzene-1,3,5-tricarboxylate (L 0 ) synthesized by hydro(solvo)thermal method forming a double layered network, in which inorganic zigzag chains of coordination Ca polyhedron are bound with organic ligands. 181 182 Different synthetic strategies are used in hydro(solvo) thermal synthesis of CPs based on the different imidazoledicarboxylic acids: imidazole-4,5-dicarboxylic, 183 2-p-methoxyphenyl-1H-imidazole-4,5-dicarboxylic, 184 1-(4-carboxybenzyl)-1H-imidazole-4,5-dicarboxylic, 185 and 2-(pyridine-3-yl)-1H-imidazole-4,5-dicarboxylic 186 acids.…”

Magnetic Nature of the CrIII–LnIII Interactions in [CrIII2LnIII3] Clusters with Slow Magnetic Relaxation

“…Among the many lanthanide‐based complexes, 3 d –4 f coordination clusters have been considered one of the most interesting molecular systems for magnetic studies . The strategy for constructing 3 d –4 f coordination clusters is to build metal cores with organic ligands, which act not only as bridging ligands to bridge 3 d and 4 f ions, but also as peripheral ligands to separate the discrete species from each other.…”

Toward a Rational Design of 3d-4f Heterometallic Coordination Polymers based on Mixed Valence Copper Centers

“…In the present work, we report two novel mixed valence Cu I /Cu II -Ln III 37 and recently two 3d-Ce III compounds (3d= Cu II , Co II ). 38 In the present work, two new HCP were prepared under solvothermal conditions.…”