Electric and magnetic properties of organic semiconductors. II. Temperature dependence of the thermo-E.M.F. of donor-acceptor complexes of substituted oligomeric leucobases of polyaniline type with iodine

1967 ◽  
Vol 32 (3) ◽  
pp. 1118-1124 ◽  
Author(s):  
V. Hádek ◽  
K. Ulbert
Keyword(s):  
Magnetic Properties ◽  
Temperature Dependence ◽  
Organic Semiconductors ◽  
Donor Acceptor

Energetic Control of Redox-Active Polymers Towards Safe Organic Bioelectronic Materials

2019 ◽  
Author(s):  
Alexander Giovannitti ◽  
Reem B. Rashid ◽  
Quentin Thiburce ◽  
Bryan D. Paulsen ◽  
Camila Cendra ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Organic Semiconductors ◽  
Side Reaction ◽  
Semiconducting Polymers ◽  
Side Reactions ◽  
Redox Active ◽  
Donor Acceptor ◽  
Electrochemical Devices ◽  
Biological Environment ◽  
Device Operation

<p>Avoiding faradaic side reactions during the operation of electrochemical devices is important to enhance the device stability, to achieve low power consumption, and to prevent the formation of reactive side‑products. This is particularly important for bioelectronic devices which are designed to operate in biological systems. While redox‑active materials based on conducting and semiconducting polymers represent an exciting class of materials for bioelectronic devices, they are susceptible to electrochemical side‑reactions with molecular oxygen during device operation. We show that this electrochemical side reaction yields hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), a reactive side‑product, which may be harmful to the local biological environment and may also accelerate device degradation. We report a design strategy for the development of redox-active organic semiconductors based on donor-acceptor copolymers that prevent the formation of H<sub>2</sub>O<sub>2</sub> during device operation. This study elucidates the previously overlooked side-reactions between redox-active conjugated polymers and molecular oxygen in electrochemical devices for bioelectronics, which is critical for the operation of electrolyte‑gated devices in application-relevant environments.</p>

Mixed Donor-Acceptor-Derived N ,N′ -Diarylpyrazine-2,5-dicarboxamido-Bridged Diruthenium Systems: Structures, Magnetic Properties, and Electronic Forms in Multiredox States

2017 ◽  
Vol 2017 (46) ◽  
pp. 5497-5506 ◽  
Author(s):  
Farheen Fatima Khan ◽  
Abhishek Mandal ◽  
Johannes Klein ◽  
José Luis Priego ◽  
Reyes Jiménez-Aparicio ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Donor Acceptor

Effects of Ta2O5 addition on the microstructure and temperature dependence of magnetic properties of MnZn ferrites

2009 ◽  
Vol 321 (5) ◽  
pp. 438-441 ◽  
Author(s):  
Lezhong Li ◽  
Zhongwen Lan ◽  
Zhong Yu ◽  
Ke Sun ◽  
Ming Luo ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Temperature Dependence ◽  
Mnzn Ferrites

Molecular Tetrominoes: Selective Masking of Donor pi-face to Control Configuration of Donor-Acceptor Complex

2021 ◽  
Author(s):  
Jenna L Sartucci ◽  
Arindam Maity ◽  
Manikandan Mohanan ◽  
Jeffery A. Bertke ◽  
Miklos Kertesz ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Organic Electronics ◽  
Molecular Design ◽  
Design Rules ◽  
Acceptor Complex ◽  
Donor Acceptor ◽  
Doping Mechanism ◽  
Control Configuration

Understanding the doping mechanism in organic semiconductors and generating molecular design rules to control the doping process is crucial to improve the performance of organic electronics. Even though controlling the...

scholarly journals The role of enzyme dynamics and tunnelling in catalysing hydride transfer: studies of distal mutants of dihydrofolate reductase

2006 ◽  
Vol 361 (1472) ◽  
pp. 1307-1315 ◽  
Author(s):  
Lin Wang ◽  
Nina M Goodey ◽  
Stephen J Benkovic ◽  
Amnon Kohen
Keyword(s):  
Temperature Dependence ◽  
Dihydrofolate Reductase ◽  
Isotope Effects ◽  
Hydride Transfer ◽  
Activation Parameters ◽  
Physical Nature ◽  
Enzyme Dynamics ◽  
Temperature Dependences ◽  
Donor Acceptor ◽  
Significant Temperature

Residues M42 and G121 of Escherichia coli dihydrofolate reductase ( ec DHFR) are on opposite sides of the catalytic centre (15 and 19 Å away from it, respectively). Theoretical studies have suggested that these distal residues might be part of a dynamics network coupled to the reaction catalysed at the active site. The ec DHFR mutant G121V has been extensively studied and appeared to have a significant effect on rate, but only a mild effect on the nature of H-transfer. The present work examines the effect of M42W on the physical nature of the catalysed hydride transfer step. Intrinsic kinetic isotope effects (KIEs), their temperature dependence and activation parameters were studied. The findings presented here are in accordance with the environmentally coupled hydrogen tunnelling. In contrast to the wild-type (WT), fluctuations of the donor–acceptor distance were required, leading to a significant temperature dependence of KIEs and deflated intercepts. A comparison of M42W and G121V to the WT enzyme revealed that the reduced rates, the inflated primary KIEs and their temperature dependences resulted from an imperfect potential surface pre-arrangement relative to the WT enzyme. Apparently, the coupling of the enzyme's dynamics to the reaction coordinate was altered by the mutation, supporting the models in which dynamics of the whole protein is coupled to its catalysed chemistry.

Temperature dependence of the magnetic properties of mono-dispersed Co0.5Zn0.5Fe2O4 microtubes derived from different templates

2018 ◽  
Vol 30 (3) ◽  
pp. 2809-2820
Author(s):  
Peng-zhao Gao ◽  
Zhi-bo Huang ◽  
Hang-bo Zheng ◽  
Xiao-pan Liu ◽  
Jin Wen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Temperature Dependence

scholarly journals Impact of ZrO2 Additive on Microstructure, Magnetic Properties, and Temperature Dependence of the Initial Permeability of LiTiZn Ferrite Ceramics

2021 ◽  
Author(s):  
Andrey Malyshev ◽  
Anna B. Petrova ◽  
Anatoly P. Surzhikov
Keyword(s):  
Magnetic Properties ◽  
Temperature Dependence ◽  
Defect Structure ◽  
Initial Permeability ◽  
Experimental Temperature ◽  
Mathematical Treatment ◽  
Experimental Temperature Dependence ◽  
Average Grain Size ◽  
Soft Ferrite ◽  
Microstructure And Magnetic Properties

Abstract The effect of the diamagnetic ZrO2 addition on the microstructure and magnetic properties of LiTiZn ferrite ceramics, including the shape and parameters of the temperature dependence of the initial permeability, has been investigated. The defect structure of ferrite ceramic samples is assessed according to our earlier proposed method based on mathematical treatment of the experimental temperature dependencies of the initial permeability. The method is recommended for defects monitoring of soft ferrite ceramics and ferrite products. It was found that the defect structure of ferrite ceramics increased by 350% with an increase in the concentration of the ZrO2 additive in the range of (0–0.5) wt.%. In this case, for the same samples, the increase in the true physical broadening of reflections is only 20%, and the coercive force by 50%. Simultaneously, the maximum of the experimental temperature dependence of the initial permeability dropped by 45%. The microstructure of all samples is characterized with a similar average grain size according to the SEM data. However, samples with the 0.5wt.% of ZrO2 are characterized by the formation of conglomerates. A linear relationship was obtained between the defect structure and the width of the reflections, which indicates that this parameter is related to the elastic stress of ferrite ceramics.

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