scholarly journals Room-temperature Pd/Ag direct arylation enabled by a radical pathway

2020 ◽  
Vol 16 ◽  
pp. 384-390
Author(s):  
Amy L Mayhugh ◽  
Christine K Luscombe
Keyword(s):  
Room Temperature ◽  
Electronic Materials ◽  
Cross Coupling ◽  
Underlying Mechanism ◽  
Conjugated Materials ◽  
Direct Arylation ◽  
Materials Development ◽  
Organic Electronic Materials ◽  
Direct Arylation Polymerization ◽  
The Cost

Direct arylation is an appealing method for preparing π-conjugated materials, avoiding the prefunctionalization required for traditional cross-coupling methods. A major effort in organic electronic materials development is improving the environmental and economic impact of production; direct arylation polymerization (DArP) is an effective method to achieve these goals. Room-temperature polymerization would further improve the cost and energy efficiencies required to prepare these materials. Reported herein is new mechanistic work studying the underlying mechanism of room temperature direct arylation between iodobenzene and indole. Results indicate that room-temperature, Pd/Ag-catalyzed direct arylation systems are radical-mediated. This is in contrast to the commonly proposed two-electron mechanisms for direct arylation and appears to extend to other substrates such as benzo[b]thiophene and pentafluorobenzene.

Poly(2,3-dihexylthieno[3,4-b]pyrazine-alt-2,3-dihexylquinoxaline): Processible, Low-Bandgap, Ambipolar-Acceptor Frameworks via Direct Arylation Polymerization

Synlett ◽  
2018 ◽  
Vol 29 (19) ◽  
pp. 2542-2546 ◽  
Author(s):  
Seth Rasmussen ◽  
Trent Anderson ◽  
Evan Culver ◽  
Furqan Almyahi ◽  
Paul Dastoor
Keyword(s):  
Cross Coupling ◽  
Organic Photovoltaic ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices ◽  
High Solubility ◽  
Direct Arylation ◽  
Low Bandgap ◽  
Direct Arylation Polymerization

The synthesis of a new dialkyl-functionalized quinoxaline ­acceptor, 5,8-dibromo-2,3-dihexylquinoxaline, is reported, along with its cross-coupling with 2,3-dihexylthieno[3,4-b]pyrazine via direct arylation polymerization. The resulting ambipolar-acceptor polymer ­poly(2,3-dihexylthieno[3,4-b]pyrazine-alt-2,3-dihexylquinoxaline) exhib­its a low bandgap of 1.07 eV and high solubility. The results of initial organic photovoltaic devices are also reported.

One and Two-dimensional Semiconducting Nanostructures Self-assembly of Conjugated Oligomers

2003 ◽  
Vol 775 ◽  
Author(s):  
Ph. Leclère ◽  
M. Surin ◽  
P. Jonkheijm ◽  
O. Henze ◽  
A.P.H.J. Schenning ◽  
...  
Keyword(s):  
Solid State ◽  
Self Assembly ◽  
Electronic Materials ◽  
Field Effect Transistors ◽  
Conjugated Materials ◽  
Light Emitting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Organic Electronic Materials ◽  
Semiconducting Nanostructures

AbstractThe properties of organic electronic materials in the solid-state are determined not only by those of individual molecules but also by those of ensembles of molecules. The ability to control the architectures of these ensembles is thus essential for optimising the properties of conjugated materials for use in electronic devices (light emitting diodes, field effect transistors, solar cells,…) and is primordial for potential technological applications in nanoelectronics.Here, we report on the observation by atomic force microscopy (AFM) of 1D and 2D nanoscale architectures obtained in the solid-state from solutions of molecularly-dissolved conjugated block copolymers or oligomers, and demonstrate that the conjugated molecules can organize onto a surface over lengthscales from nanometers to several microns, forming semiconducting fibrils by π-stacking processes.

scholarly journals Novel Diketopyrrolopyrrole-Based π-Conjugated Molecules Synthesized Via One-Pot Direct Arylation Reaction

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1760 ◽  
Author(s):  
Hui Liu ◽  
Xiao-Feng Zhang ◽  
Jing-Zhao Cheng ◽  
Ai-Guo Zhong ◽  
He-Rui Wen ◽  
...  
Keyword(s):  
High Performance ◽  
Electronic Materials ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
One Pot ◽  
Direct Arylation ◽  
Cross Coupling Reactions ◽  
Synthetic Strategy ◽  
Organometallic Precursors

Diketopyrrolopyrrole (DPP) is an important type of π-conjugated building block for high-performance organic electronic materials. DPP-based conjugated materials are usually synthesized via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this paper, a series of novel phenyl-cored DPP molecules, including five meta-phenyl-cored molecules and four para-phenyl-cored molecules, have been synthesized in moderate to good yields, in a facile manner, through the Pd-catalyzed direct arylation of C–H bonds, and their optoelectrical properties have been investigated in detail. All new molecules have been fully characterized by NMR, MALDI-TOF MS, elemental analysis, UV–visible spectroscopy, and cyclic voltammetry. This synthetic strategy has evident advantages of atom- and step-economy and low cost, compared with traditional cross-coupling reactions.

The Merger of CF3SO2Na and Palladium Catalysis to Enable Decarboxylative Cross-Coupling for the Synthesis of Aromatic Ketones under Room Temperature

2021 ◽  
Author(s):  
Pan Xie ◽  
Cheng Xue ◽  
Cancan Wang ◽  
Dongdong Du ◽  
Sanshan Shi
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Palladium Catalysis ◽  
Cross Coupling ◽  
Boronic Acids ◽  
Aromatic Ketones ◽  
Aryl Ketones ◽  
Oxocarboxylic Acids

A CF3SO2Na/Pd(OAc)2 co-catalyzed strategy is developed to produce aryl ketones via visible-light-induced decarboxylative cross-coupling of α-oxocarboxylic acids and aryl boronic acids. This process was perfomed under air at room temperature,...

scholarly journals Longevity of Raw and Lyophilized Crude Urease Extracts

2021 ◽  
Vol 2 (2) ◽  
pp. 325-334
Author(s):  
Neda Javadi ◽  
Hamed Khodadadi Tirkolaei ◽  
Nasser Hamdan ◽  
Edward Kavazanjian
Keyword(s):  
Crude Extract ◽  
Room Temperature ◽  
Low Cost ◽  
Extraction Process ◽  
Crude Extracts ◽  
Simple Extraction ◽  
Commercial Applications ◽  
Stable Source ◽  
The Stability ◽  
The Cost

The stability (longevity of activity) of three crude urease extracts was evaluated in a laboratory study as part of an effort to reduce the cost of urease for applications that do not require high purity enzyme. A low-cost, stable source of urease will greatly facilitate engineering applications of urease such as biocementation of soil. Inexpensive crude extracts of urease have been shown to be effective at hydrolyzing urea for carbonate precipitation. However, some studies have suggested that the activity of a crude extract may decrease with time, limiting the potential for its mass production for commercial applications. The stability of crude urease extracts shown to be effective for biocementation was studied. The crude extracts were obtained from jack beans via a simple extraction process, stored at room temperature and at 4 ℃, and periodically tested to evaluate their stability. To facilitate storage and transportation of the extracted enzyme, the longevity of the enzyme following freeze drying (lyophilization) to reduce the crude extract to a powder and subsequent re-hydration into an aqueous solution was evaluated. In an attempt to improve the shelf life of the lyophilized extract, dextran and sucrose were added during lyophilization. The stability of purified commercial urease following rehydration was also investigated. Results of the laboratory tests showed that the lyophilized crude extract maintained its activity during storage more effectively than either the crude extract solution or the rehydrated commercial urease. While incorporating 2% dextran (w/v) prior to lyophilization of the crude extract increased the overall enzymatic activity, it did not enhance the stability of the urease during storage.

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