scholarly journals Crystal Structures, Thermal and Luminescent Properties of Gadolinium(III) trans-1,4-Cyclohexanedicarboxylate Metal-Organic Frameworks

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1375
Author(s):  
Pavel A. Demakov ◽  
Alena A. Vasileva ◽  
Vladimir A. Lazarenko ◽  
Alexey A. Ryadun ◽  
Vladimir P. Fedin
Keyword(s):  
Crystal Structures ◽  
Metal Organic Frameworks ◽  
Luminescent Properties ◽  
Yellow Emission ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
X Ray ◽  
3D Network ◽  
Characteristic Wavelength ◽  
Metal Organic

Four new gadolinium(III) metal-organic frameworks containing 2,2’-bipyridyl (bpy) or 1,10-phenanthroline (phen) chelate ligands and trans-1,4-cyclohexanedicarboxylate (chdc2–) were synthesized. Their crystal structures were determined by single-crystal X-ray diffraction analysis. All four coordination frameworks are based on the binuclear carboxylate building units. In the compounds [Gd2(bpy)2(chdc)3]·H2O (1) and [Gd2(phen)2(chdc)3]·0.5DMF (2), the six-connected {Ln2(L)2(OOCR)6} blocks form a 3D network with the primitive cubic (pcu) topology. In the compounds [Gd2(NO3)2(phen)2(chdc)2]·2DMF (3) and [Gd2Cl2(phen)2(chdc)2]∙0.3DMF∙2.2dioxane (4), the four-connected {Ln2(L)2(X)2OOCR)4} units (where X = NO3– for 3 or Cl– for 4) form a 2D square-grid (sql) network. The solid-state luminescent properties were investigated for the synthesized frameworks. Bpy-containing compound 1 shows no luminescence, possibly due to the paramagnetic quenching by Gd3+ cation. In contrast, the phenathroline-containing MOFs 2–4 possess yellow emission under visible excitation (λex = 460 nm) with the tuning of the characteristic wavelength by the coordination environment of the metal center.

A series of microporous and robust Ln-MOFs showing luminescent properties and catalytic performances towards Knoevenagel reactions

2021 ◽  
Author(s):  
Qing-Xia Yao ◽  
Miaomiao Tian ◽  
Jun Zheng ◽  
Jintang Xue ◽  
Xuze Pan ◽  
...  
Keyword(s):  
Single Crystal ◽  
Metal Organic Frameworks ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Catalytic Performances

A series of microporous Ln(III)-based metal-organic frameworks (1-Ln) have been hydrothermally synthesized by using 4,4',4''-nitrilotribenzoic acid (H3NTB). Single crystal X-ray diffraction analyses show 1-Ln are isostructural and have 3D porous...

scholarly journals Two metal–organic frameworks based on Sr2+ and 1,2,4,5-tetrakis(4-carboxyphenyl)benzene linkers

2021 ◽  
Vol 77 (12) ◽  
Author(s):  
Muhammad Usman ◽  
Lydia Ogebule ◽  
Raúl Castañeda ◽  
Evgenii Oskolkov ◽  
Tatiana Timofeeva
Keyword(s):  
Hydrogen Bonding ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structural Control ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Solvent Systems ◽  
Semiconductor Properties

Two structurally different metal–organic frameworks based on Sr2+ ions and 1,2,4,5-tetrakis(4-carboxyphenyl)benzene linkers have been synthesized solvothermally in different solvent systems and studied with single-crystal X-ray diffraction technique. These are poly[[μ12-4,4′,4′′,4′′′-(benzene-1,2,4,5-tetrayl)tetrabenzoato](dimethylformamide)distrontium(II)], [Sr2(C34H18O8)(C3H7NO)2] n , and poly[tetraaqua{μ2-4,4′-[4,5-bis(4-carboxyphenyl)benzene-1,2-diyl]dibenzoato}tristrontium(II)], [Sr3(C34H20O8)2(H2O)4]. The differences are noted between the crystal structures and coordination modes of these two MOFs, which are responsible for their semiconductor properties, where structural control over the bandgap is desirable. Hydrogen bonding is present in only one of the compounds, suggesting it has a slightly higher structural stability.

Two isostructural fluorinated metal-organic frameworks with rare rod-packing architecture: syntheses, structures and luminescent properties

2017 ◽  
Vol 72 (2) ◽  
pp. 107-113 ◽  
Author(s):  
Sheng-Chun Chen ◽  
Feng Tian ◽  
Ming-Yang He ◽  
Qun Chen
Keyword(s):  
Fluorescence Spectra ◽  
Metal Organic Frameworks ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Solid State Fluorescence ◽  
Methyl Benzene

AbstractTwo isostructural fluorinated metal-organic frameworks, formulated as [M2(Fbix)(1,4-NDC)2]n (M=Cd for 1 and Mn for 2), were synthesized by employing 1,4-naphthalenedicarboxylic acid (1,4-H2NDC) and the flexible fluorinated ligand 2,3,5,6-tetrafluoro-1,4-bis(imidazole-1-yl-methyl)benzene (Fbix) under hydrothermal conditions. Their structures were determined by single-crystal X-ray diffraction and further characterized by infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analyses. Structure analyses have revealed that compounds 1 and 2 show an unusual hex net based on infinite rod-shaped secondary building units. The solid-state fluorescence spectra of 1 and 2 were measured and indicate a ligand-based emission for both complexes.

Urothermal Syntheses, Crystal Structures, and Luminescent Properties of Two New ZnII Compounds Constructed by the Mixed Ligands of 1,2,4-Triazole and 1,4-Naphthalenedicarboxylic Acid or 2,6-Naphthalenedicarboxylic Acid

2015 ◽  
Vol 68 (8) ◽  
pp. 1299 ◽  
Author(s):  
Haiyan Liu ◽  
Xufeng Meng ◽  
Lihui Zhang ◽  
Anqiang Jia
Keyword(s):  
Self Assembly ◽  
Metal Organic Frameworks ◽  
Luminescent Properties ◽  
The Self ◽  
X Ray Diffraction ◽  
Thermal Stabilities ◽  
X Ray ◽  
Mixed Ligands ◽  
Elemental Analyses ◽  
Metal Organic

Under urothermal conditions, the self-assembly of ZnII ions, 1,2,3-triazole, and two isomeric dicarboxylate ligands (1,4-H2ndc and 2,6-H2ndc) afforded two new metal–organic frameworks, namely [Zn(1,4-ndc)0.5(taz)]n·n(e-urea) (1) and [Zn(2,6-ndc)0.5(taz)]n·n(H2O)·n(e-urea) (2) (1,4-H2ndc = 1,4-naphthalenedicarboxylic acid; 2,6-H2ndc = 2,6-naphthalenedicarboxylic acid; Htaz = 1,2,4-triazole; e-urea = ethyleneurea), which were further determined by single-crystal X-ray diffraction analyses, elemental analyses, powder X-ray diffraction analyses, and IR spectra. Compound 1 features a 3D pillar-layered framework with 6-connected pcu topology (pcu = α-Po), and compound 2 also features a 3D pillar-layered framework with 6-connected pcu topology. In addition, the thermal stabilities and solid-state photoluminescent properties of compounds 1 and 2 were also studied.

Synthesis, crystal structure, luminescence, and photocatalytic properties of a 2D Cu(II) metal-organic frameworks based on 3,5-di(1H-benzimidazol-1-yl)pyridine and 4,4′-oxybis(benzoate) ligands

2020 ◽  
Vol 75 (8) ◽  
pp. 727-732
Author(s):  
Chen Zhang ◽  
Jian-Qing Tao
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Uv Light ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Photocatalytic Activities ◽  
Metal Organic

AbstractA new Cu(II) metal-organic framework, [Cu(L)(OBA)·H2O]n (1) [H2OBA = 4,4′-oxybis(benzoic acid), L = 3,5-di(1H-benzimidazol-1-yl)pyridine] was hydrothermally synthesized and characterized through IR spectroscopy, elemental and thermal analysis and single-crystal X-ray diffraction. Complex 1 is a four-connected uni-nodal 2D net with a (44·62) topology which shows an emission centered at λ ∼393 nm upon excitation at λ = 245 nm. Moreover, complex 1 possesses high photocatalytic activities for the decomposition of Rhodamine B (RhB) under UV light irradiation.

scholarly journals In situ X‐ray Diffraction Investigation of the Crystallisation of Perfluorinated Ce(IV)‐based Metal‐Organic Frameworks with UiO‐66 and MIL‐140 architectures

2021 ◽  
Author(s):  
Stephen J. I. Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic

scholarly journals Compressibility Studies of Zirconium Based Metal-Organic Frameworks

2014 ◽  
Vol 70 (a1) ◽  
pp. C157-C157
Author(s):  
Claire Hobday ◽  
Stephen Moggach ◽  
Carole Morrison ◽  
Tina Duren ◽  
Ross Forgan
Keyword(s):  
High Pressure ◽  
Mechanical Stability ◽  
Metal Organic Frameworks ◽  
External Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pressure Medium ◽  
Metal Organic ◽  
University Of Oslo

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.

scholarly journals Four Novel d10 Metal-Organic Frameworks Incorporating Amino-Functionalized Carboxylate Ligands: Synthesis, Structures, and Fluorescence Properties

2021 ◽  
Vol 9 ◽  
Author(s):  
Wang Xie ◽  
Jie Wu ◽  
Xiaochun Hang ◽  
Honghai Zhang ◽  
Kang shen ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Three Dimensional ◽  
Fluorescence Properties ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Quenching Effect ◽  
D10 Metal ◽  
Metal Organic ◽  
Point Symbol

By employment of amino-functionalized dicarboxylate ligands to react with d10 metal ions, four novel metal-organic frameworks (MOFs) were obtained with the formula of {[Cd(BCPAB)(μ2-H2O)]}n (1), {[Cd(BDAB)]∙2H2O∙DMF}n (2), {[Zn(BDAB)(BPD)0.5(H2O)]∙2H2O}n (3) and {[Zn(BDAB)(DBPB)0.5(H2O)]∙2H2O}n (4) (H2BCPAB = 2,5-bis(p-carbonylphenyl)-1-aminobenzene; H2BDAB = 1,2-diamino-3,6-bis(4-carboxyphenyl)benzene); BPD = (4,4′-bipyridine); DBPB = (E,E-2,5-dimethoxy-1,4-bis-[2-pyridin-vinyl]-benzene; DMF = N,N-dimethylformamide). Complex 1 is a three-dimensional (3D) framework bearing seh-3,5-Pbca nets with point symbol of {4.62}{4.67.82}. Complex 2 exhibits a 4,4-connected new topology that has never been reported before with point symbol of {42.84}. Complex 3 and 4 are quite similar in structure and both have 3D supramolecular frameworks formed by 6-fold and 8-fold interpenetrated 2D coordination layers. The structures of these complexes were characterized by single crystal X-ray diffraction (SC-XRD), thermal gravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements. In addition, the fluorescence properties and the sensing capability of 2–4 were investigated as well and the results indicated that complex 2 could function as sensor for Cu2+ and complex 3 could detect Cu2+ and Ag+via quenching effect.

scholarly journals In situ X-ray Diffraction Investigation of the Crystallisation of Perfluorinated Ce(IV)-based Metal-Organic Frameworks with UiO-66 and MIL-140 architectures

2020 ◽  
Author(s):  
Stephen Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rate Determining Step ◽  
Wide Range ◽  
Metal Organic

We report on the results of a thorough <i>in situ</i> synchrotron powder X-ray diffraction study of the crystallisation in aqueous medium of two recently discovered perfluorinated Ce(IV)-based metal-organic frameworks (MOFs), analogues of the already well investigated Zr(IV)-based UiO-66 and MIL-140A, namely, F4_UiO-66(Ce) and F4_MIL-140A(Ce). The two MOFs were originally obtained in pure form in similar conditions, using ammonium cerium nitrate and tetrafluoroterephthalic acid as building blocks, and small variations of the reaction parameters were found to yield mixed phases. Here, we investigate the crystallisation of these compounds <i>in situ</i> in a wide range of conditions, varying parameters such as temperature, amount of the protonation modulator nitric acid (HNO<sub>3</sub>) and amount of the coordination modulator acetic acid (AcOH). When only HNO<sub>3</sub> is present in the reaction environment, F4_MIL-140A(Ce) is obtained as a pure phase. Heating preferentially accelerates nucleation, which becomes rate determining below 57 °C, whereas the modulator influences nucleation and crystal growth to a similar extent. Upon addition of AcOH to the system, alongside HNO<sub>3</sub>, mixed-phased products, consisting of F4_MIL-140A(Ce) and F4_UiO-66(Ce), are obtained. In these conditions, F4_UiO-66(Ce) is always formed faster and no interconversion between the two phases occurs. In the case of F4_UiO-66(Ce), crystal growth is always the rate determining step. An increase in the amount of HNO<sub>3</sub> slows down both nucleation and growth rates for F4_MIL-140A(Ce), whereas nucleation is mainly affected for F4_UiO-66(Ce). In addition, a higher amount HNO<sub>3</sub> favours the formation of F4_MIL-140A(Ce). Similarly, increasing the amount of AcOH leads to slowing down of the nucleation and growth rate, but favours the formation of F4_UiO-66(Ce). The pure F4_UiO-66(Ce) phase could also be obtained when using larger amounts of AcOH in the presence of minimal HNO<sub>3</sub>. Based on these <i>in situ</i> results, a new optimised route to achieving a pure, high quality F4_MIL-140A(Ce) phase in mild conditions (60 °C, 1 h) is also identified.

scholarly journals Twinning in Zr-Based Metal-Organic Framework Crystals

Chemistry ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 777-786
Author(s):  
Sigurd Øien-Ødegaard ◽  
Karl Lillerud
Keyword(s):  
Crystal Structures ◽  
Metal Organic Framework ◽  
Special Importance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Ab Initio Structure ◽  
Crystal Twinning ◽  
Organic Framework

Ab initio structure determination of new metal-organic framework (MOF) compounds is generally done by single crystal X-ray diffraction, but this technique can yield incorrect crystal structures if crystal twinning is overlooked. Herein, the crystal structures of three Zirconium-based MOFs, that are especially prone to twinning, have been determined from twinned crystals. These twin laws (and others) could potentially occur in many MOFs or related network structures, and the methods and tools described herein to detect and treat twinning could be useful to resolve the structures of affected crystals. Our results highlight the prevalence (and sometimes inevitability) of twinning in certain Zr-MOFs. Of special importance are the works of Howard Flack which, in addition to fundamental advances in crystallography, provide accessible tools for inexperienced crystallographers to take twinning into account in structure elucidation.

Sign in / Sign up

Export Citation Format

Share Document