Dynamic Locking of Interfacial Side Reaction Sites Promotes Aluminum‐Air Batteries Close to Theoretical Capacity

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 (H2O2), 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 H2O2 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.

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Oxidation scheme of symmetrically disulphonated naphthidines with cerium(IV) sulphate

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19810561 ◽

1981 ◽

Vol 46 (3) ◽

pp. 561-572 ◽

Cited By ~ 3

Author(s):

Karel Komers

Keyword(s):

Sulphuric Acid ◽

Rate Constants ◽

Oxidation Product ◽

Side Reaction ◽

Reaction Scheme ◽

Second Order ◽

Intermediate Products ◽

Stable Intermediate ◽

Starting Compound ◽

Oxidation Agent

The author derived theoretical dependences of preasymptotic slopes of the currentless E-t curves (potential of an indicator redox electrode against time) on the number of equivalents, n, of added oxidation agent, assuming a reaction scheme of two consecutive concurrent second-order reactions involving the formation of intermediate products ( a side reaction of the starting compound with the final oxidation product leading to an adduct, which undergoes consecutive bimolecular oxidations leading again to the final product). The dependences enable to determine the type of the relatively stable intermediate products and the ratios of the rate constants. The theory was applied to the oxidation of four symmetrically disulphonated naphthidines with cerium(IV) sulphate in aqueous sulphuric acid and the results were substantiated spectrophotometrically

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N,N-Bis(Hexyl α-d-Acetylmannosyl) Acrylamide

Molbank ◽

10.3390/m1255 ◽

2021 ◽

Vol 2021 (3) ◽

pp. M1255

Author(s):

Atsushi Miyagawa ◽

Shinya Ohno ◽

Hatsuo Yamamura

Keyword(s):

Mass Spectrometry ◽

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Nuclear Magnetic Resonance Spectroscopy ◽

Side Reaction ◽

Resonance Spectroscopy ◽

Biological Functions ◽

Unknown Compound ◽

Acrylamide Monomer

Glycosyl monomers for the assembly of multivalent ligands are typically synthesized using carbohydrates with biological functions and polymerizable functional groups such as acrylamide or styrene introduced into the carbohydrate aglycon, and monomers polymerized using a radical initiator. Herein, we report the acryloylation of 6-aminohexyl α-mannoside and its conversion into the glycosyl monomer bearing an acrylamide group. The general acryloylation procedure afforded the desired N-hexyl acetylmannosyl acrylamide monomer as well as an unexpected compound with a close Rf value. The compounds were separated and analyzed by nuclear magnetic resonance spectroscopy and mass spectrometry, which revealed the unknown compound to be the bivalent N,N-bis(hexyl α-d-acetylmannosyl) acrylamide monomer, which contains two hexyl mannose units and one acrylamide group. To the best of our knowledge, this side reaction has not previously been disclosed, and may be useful for the construction of multivalent sugar ligands.

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Experimental and Computational Analyses of the Oxidation Mechanism of the Poly(arylsilane) Family as the Side Reaction during the Baking Process

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.0c02416 ◽

2020 ◽

Vol 124 (29) ◽

pp. 16149-16158

Author(s):

Osamu Kobayashi ◽

Kunihiro Noda ◽

Naohiko Ikuma ◽

Dai Shiota ◽

Takayoshi Ishimoto ◽

...

Keyword(s):

Oxidation Mechanism ◽

Side Reaction ◽

Baking Process ◽

Computational Analyses

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Improvement of long-term cycling performance of high-nickel cathode materials by ZnO coating

Nanotechnology Reviews ◽

10.1515/ntrev-2021-0020 ◽

2021 ◽

Vol 10 (1) ◽

pp. 210-220

Author(s):

Fangfang Wang ◽

Ruoyu Hong ◽

Xuesong Lu ◽

Huiyong Liu ◽

Yuan Zhu ◽

...

Keyword(s):

Electrochemical Performance ◽

Lithium Ion Batteries ◽

Solid Phase ◽

Low Cost ◽

Specific Capacity ◽

High Capacity ◽

Lithium Ion ◽

Side Reaction ◽

Chemical Route ◽

High Nickel

Abstract The high-nickel cathode material of LiNi0.8Co0.15Al0.05O2 (LNCA) has a prospective application for lithium-ion batteries due to the high capacity and low cost. However, the side reaction between the electrolyte and the electrode seriously affects the cycling stability of lithium-ion batteries. In this work, Ni2+ preoxidation and the optimization of calcination temperature were carried out to reduce the cation mixing of LNCA, and solid-phase Al-doping improved the uniformity of element distribution and the orderliness of the layered structure. In addition, the surface of LNCA was homogeneously modified with ZnO coating by a facile wet-chemical route. Compared to the pristine LNCA, the optimized ZnO-coated LNCA showed excellent electrochemical performance with the first discharge-specific capacity of 187.5 mA h g−1, and the capacity retention of 91.3% at 0.2C after 100 cycles. The experiment demonstrated that the improved electrochemical performance of ZnO-coated LNCA is assigned to the surface coating of ZnO which protects LNCA from being corroded by the electrolyte during cycling.

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A Novel Stoichio-Kinetic Model for the DPPH• Assay: The Importance of the Side Reaction and Application to Complex Mixtures

Antioxidants ◽

10.3390/antiox10071019 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1019

Author(s):

Lucrezia Angeli ◽

Sebastian Imperiale ◽

Yubin Ding ◽

Matteo Scampicchio ◽

Ksenia Morozova

Keyword(s):

Antioxidant Activity ◽

Kinetic Model ◽

Rate Constant ◽

High Resolution Mass Spectrometry ◽

Sinapic Acid ◽

Side Reaction ◽

Main Reaction ◽

Dpph Assay ◽

Best Fitting ◽

The Common

The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) assay is widely used to determine the antioxidant activity of food products and extracts. However, the common DPPH• protocol uses a two-point measurement and does not give information about the kinetics of the reaction. A novel stoichio-kinetic model applied in this study monitors the consumption of DPPH• by common antioxidants following the second order reaction. The fitting of such decay yields the rate constant k1, which describes the main reaction between antioxidants and DPPH•, and the rate constant k2, which is attributed to a slower side reaction considering the products generated between the transient radicals (AO•) and another molecule of DPPH•. The model was first applied to antioxidant standards. Sinapic acid, Trolox and ascorbic and chlorogenic acids did not show any side reaction. Instead gallic, ferulic and caffeic acids achieved the best fitting with k2. The products of the side reaction for these compounds were confirmed and identified with high-resolution mass spectrometry. Finally, the kinetic model was applied to evaluate the antioxidant activity of eight herbal extracts. This study suggests a new kinetic approach to standardize the common DPPH• assay for the determination of antioxidant activity.

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Chemie polyfunktioneller Moleküle, 127 PPh2-Eliminierung aus dem PP-verknüpften Phosphazen Ph2P-N=PPh2-PPh2=N-PPh2 mit [C5H5Fe(CO)(μ-CO)]2; Kristallstrukturanalyse des Phosphazen-Derivats /Chemistry of Polyfunctional Molecules, 127 PPh2 Elimination from the PP Connected Phosphazene Ph2P-N=PPh2-PPh2=N-PPh2, with [C5H5Fe(CO)(μ-CO)]2; Crystal Structure of the Phosphazene Derivative

Zeitschrift für Naturforschung B ◽

10.1515/znb-1997-0705 ◽

1997 ◽

Vol 52 (7) ◽

pp. 795-800 ◽

Cited By ~ 1

Author(s):

Jochen Ellermann ◽

Martin Schütz ◽

Frank W. Heinemann ◽

Matthias Moll ◽

Walter Bauer

Keyword(s):

Crystal Structure ◽

Structure Determination ◽

Side Reaction ◽

Redox Process ◽

Crystal Structure Determination

Abstract The reaction of Ph2P-N=PPh2-PPh2=N-PPh2 (Ph = C6H5, 2) with [CpFe(CO)(μ-CO)]2 (Cp = C5H5, 3) yields under elimination of a PPh2-group from 2 and cleavage of the Fe-Fe bond in 3 the monocyclic ferraphosphazene complex Cp(OC) (4) and Ph2P-PPh2 (5). In a side reaction the P-P bond of 2 is also cleaved in a redox process to give Cp(OC) (7). Compound 4 has been characterized by a crystal structure determination.

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Structural diversity of salts of terpyridine derivatives with europium(III) located in both, cation and anion, in comparison to molecular complexes

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2020-0053 ◽

2020 ◽

Vol 235 (8-9) ◽

pp. 353-363

Author(s):

Alexander E. Sedykh ◽

Robin Bissert ◽

Dirk G. Kurth ◽

Klaus Müller-Buschbaum

Keyword(s):

Thermal Properties ◽

Crystal Packing ◽

Side Reaction ◽

Molecular Complexes ◽

Structural Diversity ◽

Organic Ligands ◽

Ionic Complexes ◽

Structural Variability ◽

Dimeric Complexes ◽

The Common

AbstractThree salts of the common composition [EuCl2(X-tpy)2][EuCl4(X-tpy)]·nMeCN were obtained from EuCl3·6H2O and the respective organic ligands (X-tpy = 4′-phenyl-2,2′:6′,2″-terpyridine ptpy, 4′-(pyridin-4-yl)-2,2′:6′,2″-terpyridine 4-pytpy, and 4′-(pyridin-3-yl)-2,2′:6′,2″-terpyridine 3-pytpy). These ionic complexes are examples of salts, in which both cation and anion contain Eu3+ with the same organic ligands and chlorine atoms coordinated. As side reaction, acetonitrile transforms into acetamide resulting in the crystallization of the complex [EuCl3(ptpy)(acetamide)] (4). Salts [EuCl2(ptpy)2][EuCl4(ptpy)]·2.34MeCN (1), [EuCl2(4-pytpy)2][EuCl4(4-pytpy)]·0.11MeCN (2), and [EuCl2(3-pytpy)2][EuCl4(3-pytpy)]·MeCN (3) crystallize in different structures (varying in space group and crystal packing) due to variation of the rear atom of the ligand to a coordinative site. Additionally, we show and compare structural variability through the dimeric complexes [Eu2Cl6(ptpy)2(N,N′-spacer)]·N,N′-spacer (5, 6, 7) obtained from [EuCl3(ptpy)(py)] by exchanging the end-on ligand pyridine with several bipyridines (4,4′-bipyridine bipy, 1,2-bis(4-pyridyl)ethane bpa, and 1,2-bis(2-pyridyl)ethylene bpe). In addition, photophysical (photoluminescence) and thermal properties are presented.

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Photocrosslinking of EPDM Elastomers. Photocrosslinkable Compositions

Rubber Chemistry and Technology ◽

10.5254/1.3536262 ◽

1989 ◽

Vol 62 (4) ◽

pp. 592-608 ◽

Cited By ~ 13

Author(s):

J. Hilborn ◽

B. Rånaby

Keyword(s):

Crosslinking Agent ◽

Side Reaction ◽

Uv Absorption ◽

Good Match ◽

Good Solubility ◽

Uv Emission ◽

Alternating Copolymerization

Abstract EFDM rubbers can be efficiently crosslinked using multifunctional monomers. Several factors must be taken into consideration: 1. Good solubility of the crosslinking agent in the rubber is essential. 2. It is favorable to have a mechanism of crosslinking which gives an alternating addition of rubber and crosslinking agent, as in the case of the stepwise radical thiol-ene system or alternating copolymerization of bis-maleimide with the olefinic rubber. These systems utilize each radical of the photoinitiator to form crosslinks, enhance the rate of crosslinking and prevent homopolymerization of the crosslinking agent. 3. A good match of the UV absorption of the photoinitiator, the UV transmission of the rest of the system, and the UV emission from the lamp is essential. 4. Since disproportionation of photoinitiator radicals in cage is an unwanted side reaction in the rigid rubber system, it is better to choose photoinitiators that mainly recombine to reform a photoactive molecule as before scission.

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The aquation of cis-Chlorodi(methyl sulphoxide)bisethylenediaminecobalt(III), cis-Chlorodimethylformamidebisethylenediaminecobalt(III), and cis-Chlorodimethylacetamidebisethylenediaminecobalt(III) ions

Australian Journal of Chemistry ◽

10.1071/ch9661821 ◽

1966 ◽

Vol 19 (10) ◽

pp. 1821 ◽

Cited By ~ 13

Author(s):

IR Lantzke ◽

DW Watts

Keyword(s):

Solvent Molecule ◽

Chloride Ion ◽

Side Reaction ◽

Base Hydrolysis ◽

Alkaline Solutions ◽

Replacement Reaction ◽

Ph Values ◽

Trigonal Bipyramidal ◽

Entropy Of Activation ◽

Solvent Replacement

The aquation of each of three octahedral chloro(solvent)bisethylene- diaminecobalt(III) ions, involving the solvent ligands dimethyl sulphoxide (DMSO), dimethylformamide (DMF), and dimethylacetamide (DMA), has been examined in solutions of different pH. In solutions of pH less than 6, the predominant reaction is replacement of the solvent molecule by water in an SN1 process, involving a trigonal bipyramidal transition state and resulting in a mixture of the trans- and cis- chloroaquo complexes. The slow loss of chloride ion is an accompanying side reaction. In solutions of pH greater than 6 base hydrolysis becomes important, and in alkaline solutions the rate of solvent loss is too fast to measure by conventional techniques. The rate of liberation of chloride ion is also greatly increased with increasing pH. Values of the activation energy, and entropy of activation, are reported for the solvent replacement reaction at a pH of 1.90.

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