scholarly journals The Structure and Property of Two Different Metal-Organic Frameworks Based on N/O-Donor Mixed Ligands

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1129
Author(s):  
Zhiqiang Lu ◽  
Yanzhi Li ◽  
Yi Ru ◽  
Shujian Yang ◽  
Chu Hao ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Three Dimensional ◽  
Luminescent Properties ◽  
Chain Structure ◽  
Metal Centers ◽  
Structure And Property ◽  
Trimesic Acid ◽  
Mixed Ligands ◽  
1D Chain ◽  
Metal Organic

Two different metal-organic frameworks (MOFs) [Cd2(AZN)(HAZN)(btc)(Hbtc)·4H2O]·2H2O (1), and [Zn3(AZN)2(btc)2·4H2O] (2) were synthesized by the reactions of different metal salts with mixed ligands of 1-(4-(1H-imidazol-5-yl)phenyl)-1H-1,2,4-triazole (AZN) and trimesic acid (H3btc). The different metal centers in the reaction condition have important impact on the resulting structures of MOFs 1 and 2. Compound 1 is a one-dimensional (1D) chain structure, while 2 features a three-dimensional (3D) framework with 3-fold interpenetration topology of Point (Schläfli) symbol of (6·82)4(62·82·102). Furthermore, the luminescent properties have been studied for MOFs 1 and 2.

Accurate tuning of rare earth metal–organic frameworks with unprecedented topology for white-light emission

2020 ◽  
Vol 8 (4) ◽  
pp. 1374-1379 ◽  
Author(s):  
Yutong Wang ◽  
Kai Zhang ◽  
Xiaokang Wang ◽  
Xuelian Xin ◽  
Xiurong Zhang ◽  
...  
Keyword(s):  
White Light ◽  
Light Emission ◽  
Metal Organic Frameworks ◽  
Three Dimensional ◽  
Earth Metal ◽  
White Light Emission ◽  
One Dimensional ◽  
1D Chain ◽  
Secondary Building Units ◽  
Metal Organic

An unprecedented three-dimensional (3D) (3,4,5)-czkf topological framework (UPC-38) with one-dimensional (1D) chain secondary building units exhibits strong white light emission.

scholarly journals Increasing the Stability of Metal-Organic Frameworks

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Mathieu Bosch ◽  
Muwei Zhang ◽  
Hong-Cai Zhou
Keyword(s):  
Metal Organic Frameworks ◽  
Luminescent Properties ◽  
Vacuum Treatment ◽  
Donor Ligands ◽  
Gas Sorption ◽  
Nitrogen Donor Ligands ◽  
Metal Centers ◽  
Ligand Interactions ◽  
Metal Organic ◽  
The Stability

Metal-organic frameworks (MOFs) are a new category of advanced porous materials undergoing study by many researchers for their vast variety of both novel structures and potentially useful properties arising from them. Their high porosities, tunable structures, and convenient process of introducing both customizable functional groups and unsaturated metal centers have afforded excellent gas sorption and separation ability, catalytic activity, luminescent properties, and more. However, the robustness and reactivity of a given framework are largely dependent on its metal-ligand interactions, where the metal-containing clusters are often vulnerable to ligand substitution by water or other nucleophiles, meaning that the frameworks may collapse upon exposure even to moist air. Other frameworks may collapse upon thermal or vacuum treatment or simply over time. This instability limits the practical uses of many MOFs. In order to further enhance the stability of the framework, many different approaches, such as the utilization of high-valence metal ions or nitrogen-donor ligands, were recently investigated. This review details the efforts of both our research group and others to synthesize MOFs possessing drastically increased chemical and thermal stability, in addition to exemplary performance for catalysis, gas sorption, and separation.

Crystal transformation in Mn(II) metal-organic frameworks based on a one-dimensional chain precursor

2021 ◽  
Author(s):  
Yansong Jiang ◽  
Rui Liu ◽  
Yiran Gong ◽  
Yong Fan ◽  
Li Wang ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Metal Organic Frameworks ◽  
Chain Structure ◽  
Isophthalic Acid ◽  
Solvothermal Reaction ◽  
Dimensional Chain ◽  
One Dimensional ◽  
Crystal Transformation ◽  
1D Chain ◽  
Metal Organic

The solvothermal reaction of Mn(II) salts and 5-((4’-(tetrazol-5’’-yl)benzyl)oxy)isophthalic acid (H3L) affords a Mn(II) based coordination polymer Mn(HL)2(H2O)2 (1), which possess a one-dimensional (1D) chain structure. Using 1 as the precursor,...

Two new isomeric zinc(II) metal–organic frameworks based on 1,5-bis(2-methyl-1H-imidazol-1-yl)pentane and 5-methylisophthalate ligands

2017 ◽  
Vol 73 (2) ◽  
pp. 78-83
Author(s):  
Xiong-Wen Tan ◽  
Heng-Feng Li ◽  
Chang-Hong Li
Keyword(s):  
Self Assembly ◽  
Metal Organic Frameworks ◽  
Three Dimensional ◽  
Central Metal Atom ◽  
Central Metal ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Mixed Ligands ◽  
Metal Organic

Many factors, such as temperature, solvent, the central metal atom and the type of coligands, may affect the nature of metal–organic frameworks (MOFs) and the framework formation in the self-assembly process, which results in the complexity of these compounds and the uncertainty of their structures. Two new isomeric ZnIImetal–organic frameworks (MOFs) based on mixed ligands, namely, poly[[μ-1,5-bis(2-methyl-1H-imidazol-1-yl)pentane-κ2N3:N3′](μ-5-methylisophthalato-κ2O1:O3)zinc(II)], [Zn(C9H6O4)(C13H20N4)]n, (I), and poly[[μ-1,5-bis(2-methyl-1H-imidazol-1-yl)pentane-κ2N3:N3′](μ3-5-methylisophthalato-κ3O1:O1′:O3)(μ3-5-methylisophthalato-κ4O1:O1′:O3,O3′)dizinc(II)], [Zn2(C9H6O4)2(C13H20N4)]n, (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis. Complex (I) displays a two-dimensional layer net, while complex (II) exhibits a twofold interpenetrating three-dimensional framework. Both complexes show high stability and good fluorescence in the solid state at room temperature.

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.

scholarly journals Porous metal-organic frameworks incorporating mixed ligands

2014 ◽  
Vol 70 (a1) ◽  
pp. C1476-C1476
Author(s):  
Clive Oliver
Keyword(s):  
Single Crystal ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
Structural Diversity ◽  
3 Dimensional ◽  
Trimesic Acid ◽  
Mixed Ligands ◽  
Cadmium Metal ◽  
Metal Organic

Metal-organic frameworks (MOFs), infinite systems built up of metal ions and organic ligands have been extensively studied in materials and supramolecular chemistry due their structural diversity and application as porous materials, in catalysis, ion exchange, gas storage and purification. [1] A novel, 2-fold interpenetrated, pillared, cadmium metal-organic framework was synthesized using trimesic acid and 1,2-bis(4-pyridyl)ethane.[2] Single crystal X-ray analysis revealed a 2-fold interpenetrated, 3-dimensional framework which exhibits a 3,5-connected network with the Schläfli symbol of [(6^3)(6^9.8)] and hms topology. This compound exhibits a temperature-induced single-to-crystal-single-crystal (SC–SC) transformation upon the release of N,N'-dimethylformamide (stable up to 3000C). SC–SC transformation was also observed when the desolvated form absorbed selected polar and non-polar organic solvents. In addition, gas (N_2, CO_2 and N_2O) sorption experiments were performed showing 2.5% N_2, 4.5% CO_2 and 3.4% N_2O absorption by mass at room temperature and moderate gas pressures (~10 bar). A similar MOF was produced when 1,3,5-benzenetricarboxylic acid was replaced with 5-nitro-1,3-benzenedicarboxylic acid. This MOF displays 4-fold interpenetration and also maintains the host framework structure upon heating.

Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

2019 ◽  
Author(s):  
Andrew Rosen ◽  
M. Rasel Mian ◽  
Timur Islamoglu ◽  
Haoyuan Chen ◽  
Omar Farha ◽  
...  
Keyword(s):  
Density Functional ◽  
Metal Organic Frameworks ◽  
Redox Activity ◽  
Screening Methods ◽  
Bridging Ligands ◽  
Metal Centers ◽  
Computational Screening ◽  
Open Metal Sites ◽  
Metal Organic ◽  
Unsaturated Metal Sites

<p>Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O<sub>2</sub> and N<sub>2</sub> adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br<sup>-</sup>, μ-Cl<sup>-</sup>, μ-F<sup>-</sup>, μ-SH<sup>-</sup>, or μ-OH<sup>-</sup> groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O<sub>2</sub> affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O<sub>2</sub>. In contrast with O<sub>2</sub> adsorption, N<sub>2</sub> adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V<sup>2+</sup> open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl<sup>-</sup> ligands of M<sub>2</sub>Cl<sub>2</sub>(BBTA) (H<sub>2</sub>BBTA = 1<i>H</i>,5<i>H</i>-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH<sup>-</sup> groups would significantly enhance the strength of O<sub>2</sub> adsorption at the open metal sites without a corresponding increase in the N<sub>2</sub> affinity. Experimental investigation of Co<sub>2</sub>Cl<sub>2</sub>(BBTA) and Co<sub>2</sub>(OH)<sub>2</sub>(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O<sub>2</sub> at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH<sup>-</sup><sub> </sub>ligands and the presence of H-bonding interactions between the μ-OH<sup>-</sup> bridging ligands and the O<sub>2</sub> adsorbate.</p>

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