scholarly journals A “Pretender” Croconate-Bridged Macrocyclic Tetraruthenium Complex: Sizable Redox Potential Splittings despite Electronically Insulated Divinylphenylene Diruthenium Entities

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5232
Author(s):  
Nils Rotthowe ◽  
Michael Linseis ◽  
Lars Vogelsang ◽  
Nicole Orth ◽  
Ivana Ivanović-Burmazović ◽  
...  
Keyword(s):  
Close Contact ◽  
Nir Spectroscopy ◽  
Electronic Coupling ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Redox Active ◽  
Inductive Effects ◽  
Intervalence Charge Transfer ◽  
Metal Organic ◽  
The Individual

Careful optimization of the reaction conditions provided access to the particularly small tetraruthenium macrocycle 2Ru2Ph-Croc, which is composed out of two redox-active divinylphenylene-bridged diruthenium entities {Ru}-1,4-CH=CH-C6H4-CH=CH-{Ru} (Ru2Ph; {Ru} = Ru(CO)Cl(PiPr3)2) and two likewise redox-active and potentially non-innocent croconate linkers. According to single X-ray diffraction analysis, the central cavity of 2Ru2Ph-Croc is shielded by the bulky PiPr3 ligands, which come into close contact. Cyclic voltammetry revealed two pairs of split anodic waves in the weakly ion pairing CH2Cl2/NBu4BArF24 (BArF24 = [B{C6H3(CF3)2-3,5}4]- electrolyte, while the third and fourth waves fall together in CH2Cl2 / NBu4PF6. The various oxidized forms were electrogenerated and scrutinized by IR and UV/Vis/NIR spectroscopy. This allowed us to assign the individual oxidations to the metal-organic Ru2Ph entities within 2Ru2Ph-Croc, while the croconate ligands remain largely uninvolved. The lack of specific NIR bands that could be assigned to intervalence charge transfer (IVCT) in the mono- and trications indicates that these mixed-valent species are strictly charge-localized. 2Ru2Ph-Croc is hence an exemplary case, where stepwise IR band shifts and quite sizable redox splittings between consecutive one-electron oxidations would, on first sight, point to electronic coupling, but are exclusively due to electrostatic and inductive effects. This makes 2Ru2Ph-Croc a true “pretender”.

Fast Cyclohexane Oxidation Under Mild Reaction Conditions Through a Controlled Creation of Redox‐Active Fe(II/III) Sites in a Metal−Organic Framework

ChemCatChem ◽  
2019 ◽  
Vol 11 (22) ◽  
pp. 5650-5656 ◽  
Author(s):  
Ah‐Reum Kim ◽  
Sol Ahn ◽  
Tae‐Ung Yoon ◽  
Justin M. Notestein ◽  
Omar K. Farha ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Cyclohexane Oxidation ◽  
Reaction Conditions ◽  
Redox Active ◽  
Metal Organic ◽  
Organic Framework

scholarly journals Influence of structure–activity relationships on through-space intervalence charge transfer in metal–organic frameworks with cofacial redox-active units

2019 ◽  
Vol 10 (5) ◽  
pp. 1392-1400 ◽  
Author(s):  
Bowen Ding ◽  
Carol Hua ◽  
Cameron J. Kepert ◽  
Deanna M. D'Alessandro
Keyword(s):  
Charge Transfer ◽  
Metal Organic Frameworks ◽  
Redox Active Ligands ◽  
Structure Activity Relationships ◽  
Structure Activity ◽  
Redox Active ◽  
Intervalence Charge Transfer ◽  
Metal Organic

Metal–organic frameworks incorporating cofacially-aligned redox-active ligands exhibit through-space intervalence charge transfer phenomena.

Tunable Electrical Conductivity in Metal-Organic Framework Thin-Film Devices

Science ◽  
2013 ◽  
Vol 343 (6166) ◽  
pp. 66-69 ◽  
Author(s):  
A. Alec Talin ◽  
Andrea Centrone ◽  
Alexandra C. Ford ◽  
Michael E. Foster ◽  
Vitalie Stavila ◽  
...  
Keyword(s):  
Thin Film ◽  
Electrical Conductivity ◽  
First Principles ◽  
Metal Organic Framework ◽  
Electronic Devices ◽  
Electronic Coupling ◽  
Guest Molecules ◽  
Redox Active ◽  
Metal Organic ◽  
Thin Film Devices

We report a strategy for realizing tunable electrical conductivity in metal-organic frameworks (MOFs) in which the nanopores are infiltrated with redox-active, conjugated guest molecules. This approach is demonstrated using thin-film devices of the MOF Cu3(BTC)2 (also known as HKUST-1; BTC, benzene-1,3,5-tricarboxylic acid) infiltrated with the molecule 7,7,8,8-tetracyanoquinododimethane (TCNQ). Tunable, air-stable electrical conductivity over six orders of magnitude is achieved, with values as high as 7 siemens per meter. Spectroscopic data and first-principles modeling suggest that the conductivity arises from TCNQ guest molecules bridging the binuclear copper paddlewheels in the framework, leading to strong electronic coupling between the dimeric Cu subunits. These ohmically conducting porous MOFs could have applications in conformal electronic devices, reconfigurable electronics, and sensors.

Assembly of 1,2,3,4-Benzenetetracarboxylic Acid and Zinc(II) Metal Centers to a Chiral 3D Metal-organic Framework: Syntheses, Structure and Properties

2011 ◽  
Vol 66 (5) ◽  
pp. 533-537
Author(s):  
Can Ji ◽  
Shuang-Quan Zang ◽  
Jun-Yi Liu ◽  
Jia-Bin Li ◽  
Hong-Wei Hou
Keyword(s):  
Second Harmonic ◽  
Bulk Material ◽  
Metal Organic Framework ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Metal Centers ◽  
X Ray ◽  
Metal Organic ◽  
The Individual ◽  
Organic Framework

A new three-dimensional metal-organic framework {[Zn(mpda)0.5(bix)]·(H2O)1.5}n (1) (H4mpda = 1,2,3,4-benzenetetracarboxylic acid, m-bix = 1,3-bis(imidazol-1-ylmethyl)-benzene) has been synthesized and characterized by single-crystal X-ray diffraction and IR spectra. In 1, homochiral helical chains are formed in the Zn-mpda layer through spontaneous resolution by mpda4−. Such layers are further connected through the second m-bix ligand to form a 3D chiral metal-organic framework. The individual (4,4)-connected net in 1 can be specified by the Schläfli symbol (66)2(64.82). Bulk material of 1 has good second-harmonic generation (SHG) activity, approximately 0.4 times that of urea. In addition, a thermogravimetric analysis was carried out, and the photoluminescent behavior of the complex was also investigated

Two topologically different 3D CuII metal–organic frameworks assembled from the same ligands: control of reaction conditions

2019 ◽  
Vol 75 (6) ◽  
pp. 1060-1068 ◽  
Author(s):  
Shunlin Zhang ◽  
Sheng Gao ◽  
Xin Wang ◽  
Xin He ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Metal Organic Frameworks ◽  
High Water ◽  
High Dimensional ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Bifunctional Ligands ◽  
Metal Organic

Bifunctional ligands containing both carboxylic and sulfonate groups can adopt versatile coordination modes to produce novel metal–organic frameworks (MOFs) with high-dimensional networks and interesting topologies. Using 2,2′-disulfonylbiphenyl-4,4′-dicarboxylic acid (H4 L) as a linker and 4,4′-bipyridine (4,4′-bpy) as a co-ligand, two novel 3D CuII MOFs, {[Cu2(L)(4,4′-bpy)2.5(H2O)]·1.7H2O} n , (1), and {[Cu2(L)(4,4′-bpy)2]·DMA·3H2O} n , (2), have been synthesized and structurally characterized by X-ray crystallography (DMA is N,N-dimethylacetamide). MOF (1) shows an unprecedented trinodal 4,4,5-connected topology network with the Schläfli symbol (4.62.73)(43.65.7.8)(6.73.8.10), while MOF (2) indicates a binodal 4,6-connected fsc network with the Schläfli symbol (44.610.8)(44.62). MOFs (1) and (2) were further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and thermogravimetric analysis. MOF (1) shows a high water and chemical stability. The proton conductivity of (1) and CO2 adsorption of (2) were also investigated.

Synthesis of Polycarbonate Diol Catalyzed by Metal-Organic Framework Based on Zn2+ and Terephthalic Acid

2013 ◽  
Vol 634-638 ◽  
pp. 608-611
Author(s):  
Li Ping Wang ◽  
Gong Ying Wang ◽  
Fan Wang ◽  
Pin Hua Wang
Keyword(s):  
Terephthalic Acid ◽  
Metal Organic Framework ◽  
Sodium Ethoxide ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Metal Organic ◽  
Polycarbonate Diol ◽  
Double Hydroxide ◽  
Optimal Reaction ◽  
Organic Framework

Metal-organic framework based on Zn2+ and terephthalic acid (TPA) was prepared and characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was then used as the catalyst for the transesterification between diphenyl carbonate (DPC) and 1, 6-hexandiol (1,6-HD) to polycarbonate diol (PCDL). Compared to Mg-Al layered double hydroxide, triethylenediamine, sodium ethoxide and sodium methoxide, it exhibits the highest catalytic activity for the synthesis of PCDL. Under optimal reaction conditions(n(1,6-HD)/n(DPC) = 1.2, w(catalyst) = 0.03%, 198 °C), the yield of phenol is up to 90.1% in the transesterification process, and PCDL with higher Mn and lower hydroxyl value can be synthesized

Ternary gradient metal–organic frameworks

2017 ◽  
Vol 201 ◽  
pp. 163-174 ◽  
Author(s):  
Chong Liu ◽  
Nathaniel L. Rosi
Keyword(s):  
Ligand Exchange ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Exchange Reactions ◽  
Reaction Conditions ◽  
Gradient Distribution ◽  
X Ray ◽  
Cell Parameters ◽  
Unit Cells ◽  
Metal Organic

Gradient MOFs contain directional gradients of either structure or functionality. We have successfully prepared two ternary gradient MOFs based on bMOF-100 analogues, namely bMOF-100/102/106 and bMOF-110/100/102, via cascade ligand exchange reactions. The cubic unit cell parameter discrepancy within an individual ternary gradient MOF crystal is as large as ∼1 nm, demonstrating the impressive compatibility and flexibility of the component MOF materials. Because of the presence of a continuum of unit cells, the pore diameters within individual crystals also change in a gradient fashion from ∼2.5 nm to ∼3.0 nm for bMOF-100/102/106, and from ∼2.2 nm to ∼2.7 nm for bMOF-110/100/102, indicating significant porosity gradients. Like previously reported binary gradient MOFs, the composition of the ternary gradient MOFs can be easily controlled by adjusting the reaction conditions. Finally, X-ray diffraction and microspectrophotometry were used to analyse fractured gradient MOF crystals by comparing unit cell parameters and absorbance spectra at different locations, thus revealing the profile of heterogeneity (i.e. gradient distribution of properties) and further confirming the formation of ternary gradient MOFs.

Substituent effects on through-space intervalence charge transfer in cofacial metal–organic frameworks

2021 ◽  
Author(s):  
Patrick W. Doheny ◽  
Carol Hua ◽  
Bun Chan ◽  
Floriana Tuna ◽  
David Collison ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Metal Organic Frameworks ◽  
Substituent Effects ◽  
Electronic Coupling ◽  
Theory Analysis ◽  
Functional Theory ◽  
Structural Modifications ◽  
Intervalence Charge Transfer ◽  
Metal Organic

Using a combined experimental, theoretical and density functional theory analysis, important insights into the effects of structural modifications on the degree of electronic coupling and rate of electron transfer are obtained for the framework [Zn(BPPFTzTz)(tdc)]·2DMF.

Revisiting the High-Pressure Properties of the Metal-Organic Frameworks ZIF-8 and ZIF-67

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich
Keyword(s):  
High Pressure ◽  
State Of The Art ◽  
Energy Landscape ◽  
Structural Flexibility ◽  
Zeolitic Imidazolate Frameworks ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Open Questions ◽  
Metal Organic

The zeolitic imidazolate frameworks ZIF-8 and ZIF-67 harbour a series of fascinating stimuli responsive properties. Looking at their responsitivity to hydrostatic pressure as stimulus, open questions exist regarding the isotropic compression with non-penetrating pressure transmitting media. By applying a state-of-the-art high-pressure powder X-ray diffraction setup, we revisit the high-pressure behaviour of ZIF-8 and ZIF-67 up to <i>p</i> = 0.4 GPa in small pressure increments. We observe a drastic, reversible change of high-pressure powder X-ray diffraction data at <i>p</i> = 0.3 GPa, discovering large volume structural flexibility in ZIF-8 and ZIF-67. Our results imply a shallow underlying energy landscape in ZIF-8 and ZIF-67, an observation that might point at rich polymorphism of ZIF-8 and ZIF-67, similar to ZIF-4(Zn).<br>

Revisiting the High-Pressure Properties of the Metal-Organic Frameworks ZIF-8 and ZIF-67

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich
Keyword(s):  
High Pressure ◽  
State Of The Art ◽  
Energy Landscape ◽  
Structural Flexibility ◽  
Zeolitic Imidazolate Frameworks ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Open Questions ◽  
Metal Organic

The zeolitic imidazolate frameworks ZIF-8 and ZIF-67 harbour a series of fascinating stimuli responsive properties. Looking at their responsitivity to hydrostatic pressure as stimulus, open questions exist regarding the isotropic compression with non-penetrating pressure transmitting media. By applying a state-of-the-art high-pressure powder X-ray diffraction setup, we revisit the high-pressure behaviour of ZIF-8 and ZIF-67 up to <i>p</i> = 0.4 GPa in small pressure increments. We observe a drastic, reversible change of high-pressure powder X-ray diffraction data at <i>p</i> = 0.3 GPa, discovering large volume structural flexibility in ZIF-8 and ZIF-67. Our results imply a shallow underlying energy landscape in ZIF-8 and ZIF-67, an observation that might point at rich polymorphism of ZIF-8 and ZIF-67, similar to ZIF-4(Zn).<br>

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