Solvent-modulation of the structure and dimensionality in lanthanoid–anilato coordination polymers

Abstract

We show the key role that the size and shape of the solvent molecules may play in the dimensionality and structure of a series of lanthanoid-chloranilato coordination polymers. We report the synthesis, structure and magnetic properties of six different coordination polymers prepared with Er(iii) and chloranilato (C6O4Cl22- = 3,6-dichloro-2,5-dihydroxy-1,4-benzoquinone) and six different solvents: [Er2(C6O4Cl2)3(H2O)6]·10H2O (1), [Er2(C6O4Cl2)3(FMA)6]·4FMA·2H2O (2) (FMA = formamide = NH2CHO), [Er2(C6O4Cl2)3(DMSO)4]·2DMSO·2H2O (3) (DMSO = dimethy sulfoxide = Me2SO), [Er2(C6O4Cl2)3(DMF)6] (4) (DMF = dimethylformamide = Me2NCHO), [Er2(C6O4Cl2)3(DMA)4] (5) (DMA = dimethylacetamide = Me2NC(Me)O) and [Er2(C6O4Cl2)3(HMPA)(H2O)3]·H2O (6) (HMPA = hexamethylphosphormamide = (Me2N)3PO). We show how the different solvent molecules modulate and determine important structural parameters such as the coordination number and geometry, the shape and distortions of the cavities, the presence of solvent molecules in these cavities, the interlayer space and even the dimensionality of the structure.

Chloranilato-Based Layered Ferrimagnets with Solvent-Dependent Ordering Temperatures

“…At higher temperatures (around 350 • C), all compounds showed an abrupt weight loss corresponding to the decomposition and the release of the chloranilato ligand. As can be seen in the derivative plot, compound 4 needed a higher temperature (around 300 • C) to release the toluene molecule, suggesting that this molecule has a stronger interaction with the 2D lattice (probably due to the formation of H-bonds, as already observed in other anilato-based lattices) [34]. agreement with the elemental analysis in all cases (see experimental section).…”

“…A possible reason to explain this anomaly might be the formation of H-bonds between the -CH 3 group and the oxygen atoms or the chlorine atoms of the chloranilato ligand. The formation of such H-bonds has already been observed in other related Ln(III)-containing anilato-based lattices [34]. The higher temperature needed in the thermogravimetric measurements to release the toluene molecule in this compound agrees with this idea.…”

“…As can be seen in the derivative plot, compound 4 needed a higher temperature (around 300 °C) to release the toluene molecule, suggesting that this molecule has a stronger interaction with the 2D lattice (probably due to the formation of H-bonds, as already observed in other anilato-based lattices) [34].…”

“…The possibility to change the magnetic properties (ordering temperatures, magnetic behavior, or critical and coercive fields) by simply changing the solvent molecules is, therefore, a very appealing strategy to modulate T c in these series of 2D magnets. Furthermore, when using lanthanoids as metal ions, the solvent molecules also play a key structural role in these (6,3)-2D lattices [24,[29][30][31][32][33][34][35][36][37][38].…”

Coordinating Ability of Anions, Solvents, Amino Acids, and Gases towards Alkaline and Alkaline‐Earth Elements, Transition Metals, and Lanthanides

“…[23] Particularly interesting is the use of solvents of varying coordinating abilities to obtain solvent-coordinated Er III complexes whereupon the size and shape of the cavities,a sw ell as the dimensionality of the structure is determined by the coordinated solvent. [24] The preferentialc oordination of DMSO to Zn II in competition with am ethanol-rich mediumh as also been observed, [20] and other cases in whicht he choice of as olvent was made based on its coordinating abilities have also been reported. [25][26][27][28] The reactiono fN i II with at ridentate ligand in DMFy ields a precipitate that, recrystallized in am ixture of DMSO/CH 2 Cl 2 / MeOH in a1 :1:1 ratio results in ab inuclear complex with no methanol or dichloromethane, but with coordinated DMSO, the solvent of the mixture with the highest coordinating ability index.…”