Ln-MOF pseudo-merohedral twinned crystalline family as solvent-free heterogeneous catalysts

Hydrothermally promoted assembly of the multifunctional 3,5-disulfobenzoic acid (3,5-DSB) ligand with the lanthanide series and the 1,10-phenanthroline as a secondary ligand gives rise to the formation of 2D coordination polymers. The isostructural RPF-20-Ln series, with formula [Ln(3,5-DSB)(Phen)(H 2O)]·H2O (Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er, and Yb), present pseudomerohedral twinned crystals. The polymeric network consists of uninodal 2D net (43·63) layers perpendicular to the [010] direction. π-π Stacking interactions between them gives rise to the tridimensional supramolecular framework. The new compounds were tested as catalysts in acid Lewis reactions. A comparative study with other lanthanide MOFs inside the systems Ln/DSB and Ln/DSB/Phen reveals some structural facts that could improve the catalytic behavior of this kind of material. © 2014 American Chemical Society.R.D. acknowledges a FPI scholarship from Spanish Ministry of Science and Innovation (MICIN) and Fondo Social Europeo from the EU. This work has been supported by the Spanish MCYT Project MAT2010-17571, Consolider-Ingenio CSD2006-2010, MAT2011-29020-C02-02, PHAMA S2009/MAT-1756 Comunidad Autónoma de Madrid.Peer Reviewe