scholarly journals Chiral porous metal-organic frameworks with dual active sites for sequential asymmetric catalysis

2012 ◽  
Vol 468 (2143) ◽  
pp. 2035-2052 ◽  
Author(s):  
Feijie Song ◽  
Teng Zhang ◽  
Cheng Wang ◽  
Wenbin Lin
Keyword(s):  
Asymmetric Catalysis ◽  
Active Sites ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
Dicarboxylic Acids ◽  
Great Promise ◽  
Epoxide Ring ◽  
Potential Applications ◽  
Secondary Building Units ◽  
Metal Organic

Metal-organic frameworks (MOFs) are a class of organic–inorganic hybrid materials built from metal-connecting nodes and organic-bridging ligands. They have received much attention in recent years owing to the ability to tune their properties for potential applications in various areas. Properly designed MOFs with uniform, periodically aligned active sites have shown great promise in catalysing shape-, size-, chemo-, regio- and stereo-selective organic transformations. This study reports the synthesis and characterization of two chiral MOFs (CMOFs 1 and 2 ) that are constructed from Mn-salen-derived dicarboxylic acids [salen is ( R , R )- N , N ′-bis(5- tert -butylsalicylidene)-1,2-cyclohexanediamine], bis(4-vinylbenzoic acid)-salen manganese(III) chloride (H 2 L 4 ) or bis(benzoic acid)-salen manganese(III) chloride (H 2 L 3 ) and [Zn 4 (μ 4 -O)(O 2 CR) 6 ] or [Zn 5 (H 2 O) 2 (μ 3 -OH) 2 (O 2 CR) 8 ] secondary building units (SBUs), respectively. The SBUs in CMOF- 1 are connected by the linear ditopic Mn-salen-derived linkers to construct a fourfold interpenetrated isoreticular MOF (IRMOF) structure with pcu topology. In CMOF- 2 , the Mn-salen centres dimerize in a cross-linking way to form a diamondoid structure with threefold interpenetration. CMOF- 1 was examined for highly regio- and stereo-selective tandem alkene epoxidation/epoxide ring-opening reactions by using the Mn-salen andZn 4 (μ 4 -O)(carboxylate) 6 active sites, respectively. Our work demonstrated the potential utility of chiral MOFs with multiple active sites in the efficient synthesis of complex molecules with excellent regio- and stereo-controls

scholarly journals Two-dimensional metal-organic frameworks containing linear dicarboxylates

2006 ◽  
Vol 62 (5) ◽  
pp. 808-814 ◽  
Author(s):  
Samuel M. Hawxwell ◽  
Harry Adams ◽  
Lee Brammer
Keyword(s):  
Dicarboxylic Acid ◽  
Solvothermal Synthesis ◽  
Interplanar Spacing ◽  
Metal Organic Frameworks ◽  
Dicarboxylic Acids ◽  
Two Dimensional ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Gas Molecules ◽  
Solvent Molecules

The solvothermal synthesis of four two-dimensional metal-organic frameworks containing linear dicarboxylic acids as ligands for ZnII centres is described. Zn(BDC)(DMF) [(1) where BDC = benzene-1,4-dicarboxylic acid; DMF = N,N-dimethylformamide] adopts a common paddlewheel motif leading to a 44 grid network, whereas Zn3(BDC)3(EtOH)2 (2), Zn3(BDC)3(H2O)2·4DMF (3) and Zn3(BPDC)3(DMF)2·4DMF (4) each form networks with the relatively uncommon 36 topology based upon Zn3(O2CR)6 secondary building units. All contain coordinated solvent molecules, namely DMF [(1) and (4)], ethanol (2) or H2O (3). Comparison of structures (2) and (3) illustrates a clay-like flexibility in interplanar spacing which sheds light on the ability of the Zn3(BDC)3 framework to undergo desolvation and uptake of small solvent and gas molecules.

Recent Progress in Asymmetric Catalysis with Chiral Metal-Organic Frameworks

2020 ◽  
Vol 984 ◽  
pp. 195-204
Author(s):  
Meng Xi Zhang
Keyword(s):  
Asymmetric Catalysis ◽  
Active Sites ◽  
Recent Progress ◽  
Metal Organic Frameworks ◽  
Future Research ◽  
Asymmetric Catalysts ◽  
The Future ◽  
Metal Organic ◽  
Specific Reactions

Chiral metal-organic frameworks (CMOFs) have shown great promises in the applications of asymmetric catalysis with highly enantioselective. Herein, we briefly overview recent processes of MOF-based asymmetric catalysts based on a classification of reaction types. And we mainly focus on the structures and compositions of the active sites in these catalysts and their performances in specific reactions. In addition, some of their important unique features are critically emphasized alongside. Challenges of the future research are discussed also at the end of this review.

Metal-Organic Frameworks for Asymmetric Catalysis and Chiral Separations

MRS Bulletin ◽  
2007 ◽  
Vol 32 (7) ◽  
pp. 544-548 ◽  
Author(s):  
Wenbin Lin
Keyword(s):  
Asymmetric Catalysis ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Chiral Separations ◽  
Bridging Ligands ◽  
Guest Molecules ◽  
Pure Compounds ◽  
Metal Organic

Metal-organic frameworks (MOFs) are an interesting class of molecule-based hybrid materials built from metal-connecting points and bridging ligands. MOFs have received much attention, owing to their potential impact on many technological areas, including gas storage, separation, and heterogeneous catalysis. The modular nature of MOFs endows them with facile tunability, and as a result, properly designed MOFs can yield ideal heterogeneous catalysts with uniform active sites through judicious choice of the building blocks. Homochiral MOFs, which can be prepared by numerous approaches (construction from achiral components by seeding with a chiral single crystal, templating with coordinating chiral co-ligands, and building from metal-connecting nodes and chiral bridging ligands), represent a unique class of materials for the economical production of optically pure compounds, whether through asymmetric catalysis or enantioselective inclusion of chiral guest molecules in their porous frameworks. As such, homochiral MOFs promise new opportunities for developing chirotechnology. This contribution provides a brief overview of recent progress in the synthesis of homochiral porous MOFs and their applications in asymmetric catalysis and chiral separations.

scholarly journals 2D Porphyrinic Metal-Organic Frameworks Featuring Rod-Shaped Secondary Building Units

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2955
Author(s):  
Rory Elliott ◽  
Aoife A. Ryan ◽  
Aviral Aggarwal ◽  
Nianyong Zhu ◽  
Friedrich W. Steuber ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Metal Organic Frameworks ◽  
Gas Storage ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Separation ◽  
Potential Applications ◽  
Secondary Building Units ◽  
Metal Organic ◽  
Solvent Molecules

Metal-organic frameworks (MOFs) encompass a rapidly expanding class of materials with diverse potential applications including gas storage, molecular separation, sensing and catalysis. So-called ‘rod MOFs’, which comprise infinitely extended 1D secondary building units (SBUs), represent an underexplored subclass of MOF. Further, porphyrins are considered privileged ligands for MOF synthesis due to their tunable redox and photophysical properties. In this study, the CuII complex of 5,15-bis(4-carboxyphenyl)-10,20-diphenylporphyrin (H2L-CuII, where H2 refers to the ligand’s carboxyl H atoms) is used to prepare two new 2D porphyrinic rod MOFs PROD-1 and PROD-2. Single-crystal X-ray analysis reveals that these frameworks feature 1D MnII- or CoII-based rod-like SBUs that are coordinated by labile solvent molecules and photoactive porphyrin moieties. Both materials were characterised using infrared (IR) spectroscopy, powder X-ray diffraction (PXRD) spectroscopy and thermogravimetric analysis (TGA). The structural attributes of PROD-1 and PROD-2 render them promising materials for future photocatalytic investigations.

scholarly journals Single-atom active sites on metal-organic frameworks

2012 ◽  
Vol 468 (2143) ◽  
pp. 1985-1999 ◽  
Author(s):  
Marco Ranocchiari ◽  
Christian Lothschütz ◽  
Daniel Grolimund ◽  
Jeroen Anton van Bokhoven
Keyword(s):  
Heterogeneous Catalysis ◽  
Active Sites ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
Fine Tuning ◽  
Single Atom ◽  
Homogeneous Distribution ◽  
Catalytic Potential ◽  
Metal Organic ◽  
Heterogeneous And Homogeneous Catalysis

Single-site heterogeneous catalysis has been recently accepted as a novel branch of heterogeneous catalysis. Catalysts with single-atom active sites (SAHCs) allow the design and fine-tuning of the active moiety, and can potentially combine the advantages of heterogeneous and homogeneous catalysis. This study illustrates how porous metal-organic frameworks (MOFs) can be synthesized with homogeneous distribution of SAHCs. The catalytic potential of MIXMOFs is shown. A short overview of catalysis with mesoporous silica materials is described to demonstrate their importance in SAHC.

scholarly journals Heterogeneous Catalysts for the Conversion of Glucose into 5-Hydroxymethyl Furfural

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 861
Author(s):  
Christiaan H. L. Tempelman ◽  
Ryan Oozeerally ◽  
Volkan Degirmenci
Keyword(s):  
Lignocellulosic Biomass ◽  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Supported Catalysts ◽  
Metal Organic Frameworks ◽  
Reaction Conditions ◽  
Catalytic Systems ◽  
Hydroxymethyl Furfural ◽  
Potential Applications ◽  
Metal Organic

Lignocellulosic biomass, a cheap and plentiful resource, could play a key role in the production of sustainable chemicals. The simple sugars contained in the renewable lignocellulosic biomass can be converted into commercially valuable products such as 5-hydroxymethyl furfural (HMF). A platform molecule, HMF can be transformed into numerous chemical products with potential applications in a wide variety of industries. Of the hexoses contained in the lignocellulosic biomass, the successful production of HMF from glucose has been a challenge. Various heterogeneous catalysts have been proposed over the last decade, ranging from zeolites to metal organic frameworks. The reaction conditions vary in the reports in the literature, which makes it difficult to compare catalysts reported in different studies. In addition, the slight variations in the synthesis of the same material in different laboratories may affect the activity results, because the selectivity towards desired products in this transformation strongly depends on the nature of the active sites. This poses another difficulty for the comparison of different reports. Furthermore, over the last decade the new catalytic systems proposed have increased profoundly. In this article, we summarize the heterogeneous catalysts: Metal Organic Frameworks (MOFs), zeolites and conventional supported catalysts, that have been reported in the recent literature and provide an overview of the observed catalytic activity, in order to provide a comparison.

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