Magnetic Properties and Photoluminescence of Lanthanide Coordination Polymers Constructed with Conformation-Flexible Cyclohexane-Tetracarboxylate Ligands

Abstract

To investigate the effects on the physical properties of complexes with different conformations of flexible ligands, four lanthanide (Ln) coordination polymers with flexible ligand cyclohexane-1e,2a,4a,5e-tetracarboxylic acidDy, 3; Tb, 4), have been synthesized and characterized. Complexes 1 and 2 are 2D layers composed of L II ligands and [Ln 2 O 2 ] dinuclear units whereas complexes 3 and 4 are 3D coordination frameworks constructed with L IV ligands and two kinds of dinuclear units, [Ln 2 O 2 ] and [Ln 2 (COO) 2 ]. Notably, the conformations of ligands in two structures, which were different and changed from the original L I conformation to L II (e,a,e,e) and L IV (e,e,e,e) conformations, impact the construction of different structures and the magnetic properties. Complex 1 shows antiferromagnetic interactions whereas complex 3 exhibits weak ferromagnetic interactions and slow magnetic relaxation properties. Additionally, the photoluminescence of complexes 2 and 4 have been investigated.

Synthesis, crystal structures and, magnetic and photoluminescence properties of lanthanide-based metal–organic frameworks constructed with 2,5-dihydroxybenzene-1,4-dicarboxylic acid

“…The lanthanide-based metal-organic frameworks (MOFs) have drawn special consideration owing to their fascinating structures [1][2][3][4][5][6][7][8][9][10] resulting from the exible coordination environment of lanthanide(III) ions 1,5,11 and due to their distinct magnetic and optical properties arising from the 4f electrons of lanthanides. [4][5][6][11][12][13][14][15][16] These properties led to their prospective applications in catalysis, 10,17,18 gas absorption, 6,18,19 optoelectronic devices, 12,13,[20][21][22][23][24][25] sensors, 7,[26][27][28] contrast agents 29 and molecular magnetism. 5,15,16,[30][31][32] Several factors are important for the rational design of MOFs, such as the shape and binding mode of the...…”

Breathing 3D Frameworks with T-Shaped Connecting Ligand Exhibiting Solvent Induction, Metal Ions Effect and Luminescent Properties

“…Flexible PCPs were reported less frequently since the materials may become unstable when the coordination bonds and/or weak supramolecular interactions are changed. Flexible frameworks were assembled through flexible carboxylate ligands in our previous work [19], and it is of great importance for us to deepen the strategy to the construction with rigid ligands. Another reason for choosing rigid ligands is that the construction and regulation of PCPs becomes simplified.…”

Synthesis of Europium-doped Fluorapatite Nanorods and Their Multifunctional Biomedical Applications

“…Some lanthanide ion-doped materials (Eu 3+ or Tb 3+ ) can emit visible fluorescence (i.e., green or red) when excited by ultraviolet or blue excitation wavelengths. In comparison to fluorescent dyes or semiconductor quantum dots (QDs), these lanthanide-doped nanoparticles are advantageous due to their photostability, sharp visible emission bandwidth, and nontoxicity [6][7][8]. In previous cell labeling and tracking studies, lanthanide ion-doped fluorapatite exhibited long excited state lifetimes and no toxicity to bone marrow mesenchymal stem cells [9,10].…”