scholarly journals Fluorescence Emission Behaviors of the L-Cysteine/Au(I) Complex in a Cyclodextrin-Based Metal-Organic Framework

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1555
Author(s):  
Wataru Michida ◽  
Anna Nagai ◽  
Mina Sakuragi ◽  
Tadashi Okobira ◽  
Katsuki Kusakabe
Keyword(s):  
Fluorescence Intensity ◽  
Metal Organic Framework ◽  
Fluorescence Emission ◽  
Concentration Quenching ◽  
Thermal Motion ◽  
Dilute Solution ◽  
Crystallization Method ◽  
Total Fluorescence ◽  
Metal Organic ◽  
Organic Framework

Aggregation-induced emission (AIE) molecules are nonemissive in dilute solution but emit intensely upon aggregation in complete contrast to aggregation-caused quenching (ACQ) molecules. The emission of ACQ molecules, such as fluorescein, that have been encapsulated into the hydrophilic nanopores in a cyclodextrin-based metal-organic framework (CD-MOF) was reported to be enhanced due to the disappearance of concentration quenching and the restriction of thermal motion. However, the contribution of the restriction of thermal motion in CD-MOF could not be elucidated. In this study, an AIE-active L-cysteine/Au(I) (L-Cys/Au(I)) complex was synthesized and introduced into the nanopores of CD-MOF via a co-crystallization method. We determined the amount and chemical composition of the L-Cys/Au(I) complex in CD-MOF. The fluorescence intensity of the L-Cys/Au(I)@CD-MOF composite was investigated. The L-Cys/Au(I) complex that was synthesized from Au(III) chloride and L-cysteine was found to be a linear oligomer consisting of Cys5Au4. For the L-Cys/Au(I)@CD-MOF composite with a L-Cys/Au(I) complex of 0.45 per hydrophilic nanopore, the total fluorescence intensity of the isolated L-Cys/Au(I) complex in CD-MOF exceeded that of the L-Cys/Au(I) complex in the solid-state due to the restriction of the thermal motion without the aggregation of the complex.

scholarly journals Impact of nanosizing a host matrix based on a metal–organic framework on solid-state fluorescence emission and energy transfer

2022 ◽  
Author(s):  
Hikaru Sakamoto ◽  
Akitaka Ito ◽  
Masataka Ohtani
Keyword(s):  
Energy Transfer ◽  
Solid State ◽  
Metal Organic Framework ◽  
Fluorescence Emission ◽  
Dye Molecules ◽  
Host Matrix ◽  
Metal Organic ◽  
Solid State Fluorescence ◽  
Organic Framework

We demonstrate that the nanosize effect appears to affect the properties of dye molecules encapsulated in the pores of a metal–organic framework (dye@MOF). The emissive properties of the nanosized dye@MOF...

scholarly journals A fluorescent paramagnetic Mn metal–organic framework based on semi-rigid pyrene tetracarboxylic acid: sensing of solvent polarity and explosive nitroaromatics

IUCrJ ◽  
2015 ◽  
Vol 2 (5) ◽  
pp. 552-562 ◽  
Author(s):  
Alankriti Bajpai ◽  
Arindam Mukhopadhyay ◽  
Manchugondanahalli Shivakumar Krishna ◽  
Savitha Govardhan ◽  
Jarugu Narasimha Moorthy
Keyword(s):  
Metal Ions ◽  
Metal Organic Framework ◽  
Energy Charge ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Accessible Volume ◽  
Polarity Parameter ◽  
Metal Organic ◽  
Paramagnetic Metal ◽  
Organic Framework

An Mn metal–organic framework (Mn-MOF), Mn-L, based on a pyrene-tetraacid linker (H4L), displays a respectable fluorescence quantum yield of 8.3% in spite of the presence of the paramagnetic metal ions, due presumably to fixation of the metal ions in geometries that do not allow complete energy/charge-transfer quenching. Remarkably, the porous Mn-LMOF with ∼25% solvent-accessible volume exhibits a heretofore unprecedented solvent-dependent fluorescence emission maximum, permitting its use as a probe of solvent polarity; the emission maxima in different solvents correlate excellently with Reichardt's solvent polarity parameter (ETN). Further, the applicability of Mn-Lto the sensing of nitroaromaticsviafluorescence quenching is demonstrated; the detection limit for TNT is shown to be 125 p.p.m. The results bring out the fact that MOFs based on paramagnetic metal ions can indeed find application when the quenching mechanisms are attenuated by certain geometries of the organic linkers of the MOF.

A new three-dimensional twofold interpenetrated cadmium(II) metal–organic framework: synthesis, structure and photoluminescence properties

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Hong-Tao Zhang ◽  
Xiao-Long Wang
Keyword(s):  
Metal Organic Framework ◽  
Three Dimensional ◽  
Fluorescence Emission ◽  
Functional Materials ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Design And Synthesis ◽  
Metal Organic ◽  
Organic Framework

The design and synthesis of metal–organic frameworks (MOFs) have attracted much interest due to the aesthetics of their crystalline architectures and their potential applications as new functional materials. A new twofold interpenetrated three-dimensional (3D) MOF, namely, poly[[triaqua(μ4-(2R,2′R)-2,2′-{[1,4-phenylenebis(carbonyl)]bis(azanediyl)}dipropionato-κ7 O 1:O 1,O 1′:O 4:O 4,O 4′,O 4′′)(μ3-(2R,2′R)-2,2′-{[1,4-phenylenebis(carbonyl)]bis(azanediyl)}dipropionato-κ3 O 1:O 4:O 4)dicadmium(II)] dihydrate], {[Cd2(C14H14N2O6)2(H2O)3]·2H2O} n , (I), has been synthesized by the reaction of Cd(CH3COO)2·2H2O with the synthesized ligand (2R,2′R)-2,2′-{[1,4-phenylenebis(carbonyl)]bis(azanediyl)}dipropionic acid (H2 L). Single-crystal X-ray diffraction analysis reveals that the carboxylate groups from two crystallographically independent L 2− dianions link the cadmium cations into a one-dimensional helical secondary building unit (SBU). The resulting SBUs are extended into a 3D metal–organic framework via the terephthalamide moiety of the ligand as a spacer. In the crystal, two independent MOFs interpenetrate each other, thus producing a twofold interpenetrated 3D architecture, which shows an unprecedented 2-nodal (7,9)-connected net with the point (Schläfli) symbol (37·46·58)(38·411·516·6). MOF (I) was further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and thermogravimetric analysis. The photoluminescence properties and UV–Vis absorption spectrum of (I) have also been investigated. The MOF exhibits enhanced fluorescence emission with a high photoluminescence quantum yield of 31.55% and a longer lifetime compared with free H2 L.

scholarly journals Preparation of Co-porphyrin catalyst encapsulated in cyclodextrin-based metal-organic framework for coupling reaction

2021 ◽  
Vol 287 ◽  
pp. 02008
Author(s):  
A Nagai ◽  
T Hontake ◽  
Y Abe ◽  
W Michida ◽  
H. Inokawa ◽  
...  
Keyword(s):  
Catalyst Concentration ◽  
Metal Organic Framework ◽  
Coupling Reaction ◽  
Water Soluble ◽  
Nanoporous Structure ◽  
Oxidative Coupling Reaction ◽  
Crystallization Method ◽  
Metal Organic ◽  
Organometallic Catalyst ◽  
Organic Framework

Immobilization of organometallic catalyst were attempted by using cyclodextrin-based metal-organic framework (CD-MOF) with the characteristic nanoporous structure. Water-soluble Co(II)TCPP was prepared as an organometallic catalyst and introduced into hydrophilic nanopores in CD-MOF by co-crystallization method. In order to evaluate the catalytic properties of the obtained Co(II)TCPP/CDMOF, the oxidative coupling reaction of creosol was performed. At a catalyst concentration of 0.2 mol%, the catalytic activity of the heterogeneous Co(II)TCPP/CDMOF catalyst was almost the same as that of the homogeneous Co(II)TCPP catalyst. The conversion for Co(II)TCPP/CD-MOF catalyst reached 92% after 2-hour reaction.

Synthesis, structures, and fluorescence properties of one novel Cobalt metal–organic framework based on a tetraphenylethene-core ligand

2019 ◽  
Vol 44 (3-4) ◽  
pp. 193-197
Author(s):  
Xiudian Xu ◽  
Yu Liang ◽  
Junfeng Li ◽  
Lei Zhou ◽  
Li-Zhuang Chen ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Three Dimensional ◽  
Fluorescence Emission ◽  
Dimensional Structure ◽  
Cobalt Metal ◽  
One Dimensional ◽  
Metal Organic ◽  
The One ◽  
Mixture Of Ligands ◽  
Organic Framework

A new three-dimensional luminescent cobalt (II) metal–organic framework, [Co(Titpe)(bcpf)·(DMF)]·(H2O)2·(DMF) (compound 1, JUST-8) (Titpe = 1,1,2,2-tetrakis(4-(1H-imidazol-1-yl)phenyl)ethane, bcpf = 4,4′-sulfonyldibenzoic acid; DMF =  N, N-dimethylformamide), has been solvothermally synthesized by using CoCl2·6H2O and a mixture of ligands: Titpe ligand and bcpf ligand. Single crystal X-ray analysis reveals that 1 crystallizes in the triclinic system and [Formula: see text] space group with a = 13.2097(14) Å, b = 13.9519(14) Å, c = 14.4413(15) Å, α = 89.949(7)°, β = 70.303(7)°, γ = 80.322(7)°, V = 2465.7(5) Å3, Z = 2, Mr =1032.97, Dc = 1.391 g/cm3, μ = 0.455 mm−1, F(000) = 1070, R = 0.0585, and wR = 0.1540 for 8674 observed reflections ( I > 2σ( I)). Its overall structure is a double-fold interpenetrated framework, and it shows a porosity of 12.97% based on a calculation by PLATON and a 4- c type topological network with the point symbol of {6^5.8}. The Co atom bridges the Titpe ligands to form the one-dimensional chains into a two-dimensional layered structure and then connects the auxiliary ligands to get a three-dimensional structure. Compound 1 showed a blue fluorescence emission with the peak maximum at 431 nm (λex = 314 nm).

Solvothermal Synthesis, Structure, Fluorescence and Magnetism Properties of a Novel 3D Metal-Organic Framework Based on Tetranuclear Copper Secondary Building Units

2013 ◽  
Vol 834-836 ◽  
pp. 543-549
Author(s):  
Lei Wu ◽  
Ming Xue ◽  
Gérald Chaplais ◽  
Guang Shan Zhu ◽  
Shi Lun Qiu ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Three Dimensional ◽  
Fluorescence Emission ◽  
Ferromagnetic Interaction ◽  
One Dimensional ◽  
Dimensional Network ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Solvothermal Conditions ◽  
Organic Framework

A novel 3D metal-organic framework based on tetranuclear copper Secondary Building Units, [Cu2(μ3-OH)(4-oip)(DMF)]·DMF·2H2O (JUC-76) (4-oip = 4-hydroxyisophthalic, DMF =N,N-dimethylformamide, and JUC = Jilin University China), has been synthesized under solvothermal conditions. It crystallizes in monoclinic symmetry with space groupP21/n. JUC-76 possesses a three-dimensional network with one-dimensional rhombic channels of approximately 13.6 × 8.5 Å2along the [100] direction. The resulting structure of JUC-76 is a distorted rutile topology with one 3-connected organic node and one 6-connected inorganic node. And its Schläfli symbol is (4·62)2(42·610·83). In addition, JUC-76 exhibits fluorescence emission at 446 nm, and a dominant anti-ferromagnetic interaction between the Cu (II) ions.

Multifunctional metal–organic framework heterostructures for enhanced cancer therapy

2021 ◽  
Author(s):  
Jintong Liu ◽  
Jing Huang ◽  
Lei Zhang ◽  
Jianping Lei
Keyword(s):  
Cancer Therapy ◽  
General Principle ◽  
Biomedical Applications ◽  
Metal Organic Framework ◽  
Metal Organic ◽  
Functional Modulation ◽  
Organic Framework

We review the general principle of the design and functional modulation of nanoscaled MOF heterostructures, and biomedical applications in enhanced therapy.

Magnetic Ordering via Itinerant Ferromagnetism in a Metal-Organic Framework

2020 ◽  
Author(s):  
Jesse Park ◽  
Brianna Collins ◽  
Lucy Darago ◽  
Tomce Runcevski ◽  
Michael Aubrey ◽  
...  
Keyword(s):  
Charge Transport ◽  
Magnetic Order ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Magnetic Ordering ◽  
Double Exchange ◽  
Itinerant Ferromagnetism ◽  
Organic Solids ◽  
Metal Organic ◽  
Organic Framework

<b>Materials that combine magnetic order with other desirable physical attributes offer to revolutionize our energy landscape. Indeed, such materials could find transformative applications in spintronics, quantum sensing, low-density magnets, and gas separations. As a result, efforts to design multifunctional magnetic materials have recently moved beyond traditional solid-state materials to metal–organic solids. Among these, metal–organic frameworks in particular bear structures that offer intrinsic porosity, vast chemical and structural programmability, and tunability of electronic properties. Nevertheless, magnetic order within metal–organic frameworks has generally been limited to low temperatures, owing largely to challenges in creating strong magnetic exchange in extended metal–organic solids. Here, we employ the phenomenon of itinerant ferromagnetism to realize magnetic ordering at <i>T</i><sub>C</sub> = 225 K in a mixed-valence chromium(II/III) triazolate compound, representing the highest ferromagnetic ordering temperature yet observed in a metal–organic framework. The itinerant ferromagnetism is shown to proceed via a double-exchange mechanism, the first such observation in any metal–organic material. Critically, this mechanism results in variable-temperature conductivity with barrierless charge transport below <i>T</i><sub>C</sub> and a large negative magnetoresistance of 23% at 5 K. These observations suggest applications for double-exchange-based coordination solids in the emergent fields of magnetoelectrics and spintronics. Taken together, the insights gleaned from these results are expected to provide a blueprint for the design and synthesis of porous materials with synergistic high-temperature magnetic and charge transport properties. </b>

Solvent-Free Powder Synthesis and MOF-CVD Thin Films of the Mesoporous Metal-Organic Framework MAF-6

2019 ◽  
Author(s):  
Timothée Stassin ◽  
Ivo Stassen ◽  
Joao Marreiros ◽  
Alexander John Cruz ◽  
Rhea Verbeke ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Metal Organic Framework ◽  
Chemical Vapor ◽  
Uptake Capacity ◽  
Powder Synthesis ◽  
Crystalline Films ◽  
Metal Organic ◽  
Mesoporous Metal ◽  
First Time ◽  
Organic Framework

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.

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