Isoreticular Lanthanide Metal‐Organic Frameworks: Syntheses, Structures and Photoluminescence of a Family of 3D Phenylcarboxylates

Abstract

Five isoreticular lanthanide (Ln) metal‐organic frameworks (MOFs) – Er(bdc)(HCOO) (1a), Dy(bdc)(HCOO) (1b), Tb(bpdc)(HCOO) (2a), Gd(bpdc)(HCOO) (2b) and Tb(bpydc)(HCOO) (3) (bdc = 1,4‐benzenedicarboxylate, bpdc = 4,4′‐biphenyldicarboxylate and bpydc = 2,2′‐bipyridine‐5,5′‐dicarboxylate) – were synthesized under solvothermal conditions. The complexes were characterized by powder X‐ray diffraction, elemental analyses, infrared spectroscopy and single‐crystal X‐ray crystallography. Each LnIII ion is eight‐coordinated and forms a binuclear pseudo‐paddlewheel secondary building unit (SBU), [Ln2(CO2)2(CO2)2]. The SBUs are interconnected into 2D Ln–carboxylate nets, which act as tertiary building units (TBUs) that are linked by the rigid organic linkers to form 3D pillared frameworks. Preliminary luminescence studies reveal that energy transfer from Tb3+ to Eu3+ trace impurities is active in crystals of 2a and 3 and contributes to interesting temperature‐dependent photoluminescence. At 298 K, under UV excitation, 2a is lilac and 3 glows bright red, whereas at 77 K both 2a and 3 emit green light. Together with the previously published Tb(bdc)(HCOO), Eu(bdc)(HCOO), Gd(bdc)(HCOO) and Ln(bpedc)(HCOO) (bpedc = biphenylethene‐4,4′‐dicarboxylate), these complexes form the first examples of isoreticular LnMOFs.

Multifunctional Aromatic Carboxylic Acids as Versatile Building Blocks for Hydrothermal Design of Coordination Polymers

“…Another example concerns a Eu(III) derivative [Eu2(µ4-pyip)3(H2O)4]n·2nDMF·3nH2O (52) that is capable of emitting different colors ranging from yellow to red and orange. [Tb(µ4-bpydc)(µ3-HCOO)]n 614, 541 red-orange (298 K), green (77 K) [64] (a) (b) …”

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.…”

Synthesis, structures and luminescence properties of metal-organic frameworks based on lithium lanthanide and terephthalate

“…Metal-organic frameworks (MOFs), as an important class of advanced functional materials, have received extensive attention due to their great potential application in various research areas, such as gas adsorption/storage [1][2][3][4][5], liquid separation [6], drug delivery [4,7], and heterogeneous catalysis [8][9][10]. Among different classes of MOFs, lanthanide MOFs (LnMOFs) [11][12][13][14][15], which can be synthesized using a wide range of lanthanide cations and organic ligands, have been investigated in the fields of coordination chemistry, inorganic chemistry, and material chemistry, not only for their diverse architectures due to high coordination numbers and large ionic radii of lanthanide cations, but also for the potential applications in the field of luminescence [13][14][15][16][17][18][19][20][21], because of their increased brightness and emission quantum yield [22,23], and also in magnetism [11,[24][25][26][27][28]. To obtain functional MOFs, considerable efforts have been made and tremendous progress has been achieved.…”