Size‐Dependent Self‐Assembly of Lanthanide‐Based Coordination Frameworks with Phenanthroline‐2,9‐dicarboxylic Acid as a Preorganized Ligand in Hybrid Materials

Abstract

A family of lanthanide‐based inorganic–organic hybrids, [Ce4(PDA)4(H2O)9(SiW12O40)]·6H2O (1, PDA = 1,10‐phenanthroline‐2,9‐dicarboxylic acid), [Nd5(PDA)5(H2O)13(OH)(SiW12O40)]·8H2O (2), [Sm3(PDA)2(H2O)13(OH)(SiW12O40)]·16.5H2O (3), and [Dy4(PDA)4(H2O)11(SiW12O40)]·7H2O (4), has been hydrothermally synthesized with the [SiW12O40]4– Keggin‐type anion as a building block. Characterization by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), and single‐crystal X‐ray diffraction revealed that 1–4 are all coordination polymers with different structural features owing to the lanthanide‐contraction effect. Compound 1 is composed of cationic layers interconnected by Keggin anions in three dimensions. Compounds 2 and 3 are 1D rectangular tubelike and 1D ladderlike coordination polymers, respectively. The Keggin anion appears to play a different role in each of these hybrid structures, as its coordination mode varies between mono‐, bi‐, and tetradentate in 3, 1, and 2, respectively. In 4, the Keggin anions only reside in the interspace between two adjacent 2D cationic layers as discrete counterions. Magnetic measurements indicate that 4 exhibits frequency‐dependent alternating‐current (ac) magnetic susceptibilities indicative of slow relaxation of the magnetization.

Crystal structure of diaquatris(benzohydrazide-κ2 N,O)(isophthalato-κO)samarium(III) nitrate

“…2, with the Sm-N and the Sm-O bond lengths in the ligand ranging from 2.633 (2) to 2.694 (2) Å and 2.340 (2) to 2.478 (2) Å , respectively, and the N/O-Sm-N/O bond angles fall in the range 60.97 (6) to 145.24 (6) . These values are comparable to other reported values for oxygen/nitrogen-coordinated Sm III complexes (Alipour et al, 2016;An et al, 2016).…”

Surface-grafted lanthanoid complexes of the tungstosilicate polyanion [SiW12O40]4−: a synthetic, structural and computational investigation

“…The structures of PDA complexes with lanthanoid ions exemplify how a metal ion with an appropriate size can bind to all four donor atoms of the pocket, with M-N and M-O bond lengths in the expected ranges. In addition, if comparatively small ions are present (for instance, mode IV), two M-O bonds are formed at the expense of an elongation of the M-N bonds (Alipour et al, 2016).…”

“…POMs themselves can form one-to three-dimensional polymeric structures (Mandic et al, 2013;Ritchie et al, 2008;Streb et al, 2007), while their hybrids can be either covalent POM-based MOFs or supramolecular MOFs (SMOFs). The organic ligand (flexible or rigid), the POM charge and the oxidation state of the metal affect the hybrid structure (Alipour et al, 2016;Mirzaei, Eshtiagh-Hosseini, Alipour et al, 2015;Najafi et al, 2016). Moreover, the reaction conditions, such as temperature, time, pH, solvothermal, reflux, etc., are also very important for the final architecture of either MOFs or SMOFs.…”

“…Our group has previously used organic ligands like 4-hydroxypyridine-2,6-dicarboxylic acid (H 2 pydc-OH) and 1,10phenanthroline-2,9-dicarboxylic acid (PDA) to study the structural variations of POM-based MOFs (Fig. S2 in the supporting information) (Najafi & Mirzaei, 2017;Alipour et al, 2016;Lotfian et al, 2014;Mirzaei, Eshtiagh-Hosseini, Lotfian et al, 2014). In this article, we report the synthesis of two inorganic-organic hybrid materials based on Keggin-type tungstosilicates using these ligands; these are {Na[Dy-…”

Synthesis of Pyrazolo‐[4́,3́:5,6]pyrido[2,3‐d]pyrimidine‐diones Catalyzed by a Nano‐sized Surface‐Grafted Neodymium Complex of the Tungstosilicate via Multicomponent Reaction

“…The lower charge density on the spherical surface of HPAs is the most main reason that they are commonly employed as acidic catalysts. Due to the interest in POM‐based coordination complexes, in the last years, our research team introduced different lanthanoid coordination complexes into the POMs systems and obtained a series of novel POM‐based lanthanide clusters, which demonstrated unusual topologies and improved properties …”