Syntheses, structures, and properties of 3D lanthanide coordination polymers based on pyridine-2,3,5,6-tetracarboxylate

Syntheses, Structures, and Properties of the 3D Lanthanide Organic Frameworks with N‐Heterocyclic Polycarboxylic Acids

“…Complexes 3 and 4 show similar 3D architectures and they are isostructural with three Nd III , Dy III , Er III complexes with the ligand pdtc 4– reported earlier,11 in which Ln III ions are eight‐coordinate and adopt square antiprismatic arrangements. All the carboxyl groups of the ligand are deprotonated, and show rich coordinated modes, whereas each pdtc 4– participate coordination through a tridecadentate mode (Figures S6 and S7, Supporting Information).…”

Single-Molecule-Magnet Behavior and Fluorescence Properties of 8-Hydroxyquinolinate Derivative-Based Rare-Earth Complexes

“…At room temperature, the χ M T values are 46.66 ( 3 ) and 55.03 ( 4 ) cm 3 K mol –1 , respectively, which are in good agreement with the expected values of 47.28 and 56.68 for four uncoupled Ln III ions ( 7 F 6 , g = 3 / 2 for Tb III ; 6 H 15/2 , g = 4 / 3 for Dy III ). As the temperature is lowered, the χ M T values of complexes 3 and 4 gradually decrease from 300 to 50 K and then further decrease rapidly to reach a minimum of 36.73 cm 3 K mol –1 for 3 and 30.61 cm 3 K mol –1 for 4 at 2 K. The drop of χ M T for both complexes is due to depopulation of the M J sublevel and antiferromagnetic interactions between Ln ions …”

Noncovalent Interactions at Lanthanide Complexes

“…In fact, an effective decoration of organic ligands with noncovalent bond donor or acceptor sites allows to modify the secondary coordination sphere of lanthanide complexes and the extension of low-dimensional chains into high-dimensional supramolecular architectures via strong and directional intermolecular interactions. [49][50][51] The key function/properties of lanthanide materials have often relied on the design of the primary coordination sphere of Ln, but it has also been found that due to a ligand modification and unique "antenna effect" on the secondary coordination sphere the lanthanide complexes can exhibit extremely sharp pure-colour emissions, large Stokes shifts and long luminescence lifetimes. [52][53][54][55] Moreover, not only well explored noncovalent interactions (H-bonding, cation-π, anion-π and π-π interactions), but also the integration of new types of weak bonds (halogen, chalcogen, tetrel and triel bonds) to the coordination chemistry of lanthanides, provide a highly important strategy for the generation of novel functional materials.…”

“…properties, [33–48] which can eventually be improved by suitable functionalization of organic ligands. In fact, an effective decoration of organic ligands with noncovalent bond donor or acceptor sites allows to modify the secondary coordination sphere of lanthanide complexes and the extension of low‐dimensional chains into high‐dimensional supramolecular architectures via strong and directional intermolecular interactions [49–51] . The key function/properties of lanthanide materials have often relied on the design of the primary coordination sphere of Ln, but it has also been found that due to a ligand modification and unique “antenna effect” on the secondary coordination sphere the lanthanide complexes can exhibit extremely sharp pure‐colour emissions, large Stokes shifts and long luminescence lifetimes [52–55] …”