Water‐soluble 17 and 23 kDa polypeptides restore oxygen evolution activity by creating a high‐affinity binding site for Ca2+ on the oxidizing side of Photosystem II
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Oxidizing agent
Molecular oxygen
Side chain
Oxygen evolution
It is a well-known fact that aluminum is an amphoteric compound and is corroded by acid and alkali. In the present study, small quantities of oxidizing agent and reducing agent were added to acid and alkali and their effects on corrosion were examined.For the experiments, HCl, H2SO4 and HNO3 were used as acids, NaOH as alkali, KMnO4 and K2Cr2O7 as oxidizing agents, and SnCl2 and NaHSO3 as reducing agents.The result revealed that corrosion was most active when SnCl2 was used, and was next active in the cases of KMnO4 and K2Cr2O7.From the above fact, it has become known that coexistence of heavy metal ions, no matter whether they are oxidizing agents or reducing agents, accelerates corrosion.Similar experiments were carried out on duralumin.
Oxidizing agent
Reducing agent
Cleaning agent
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Abstract The temperature and oxygen partial pressure of the environment of a solid may produce non‐oxidizing or oxidizing conditions for any of the components in the surface. Under non‐oxidizing (free surface) conditions, one of the components of a binary alloy segregates. The oxidizing effect may enhance or diminish its surface content, and the other component may even segregate. This effect is investigated here using the experimental results (ISS and AES) and theoretical calculations of a new method. Agreement between theory and experiment is shown for AuPd and CuPd, and as well for S‐contaminated CuFe.
Oxidizing agent
Oxygen pressure
Partial pressure
Component (thermodynamics)
Atmospheric oxygen
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Abstract Photosynthetic oxygen evolution is performed at the Mn cluster in photosystem II (PSII). The advent of this reaction on ancient Earth changed its environment by generating an oxygenic atmosphere. However, how oxygen evolution originated during the PSII evolution remains unknown. Here, we characterize the site-directed mutants at the carboxylate ligands to the Mn cluster in cyanobacterial PSII. A His residue replaced for D1-D170 is found to be post-translationally converted to the original Asp to recover oxygen evolution. Gln/Asn residues in the mutants at D1-E189/D1-D342 are also converted to Glu/Asp, suggesting that amino-acid conversion is a common phenomenon at the ligand sites of the Mn cluster. We hypothesize that post-translational generation of carboxylate ligands in ancestral PSII could have led to the formation of a primitive form of the Mn cluster capable of partial water oxidation, which could have played a crucial role in the evolutionary process of photosynthetic oxygen evolution.
Oxygen evolution
Carboxylate
Oxygen-evolving complex
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Although H2S2O8 shows weak oxidizing property at room temperature, it works as a strong oxidizing agent at higher temperature via H2SO5 to H2O2 finally and therefore it had been used only as an oxidizing agent. However, H2O2 oxidizes compounds of lower valency, while it reduces that of higher valency, namely it reduces oxidizing compounds and so H2S2O8, which converted to H2O2 at higher temperature is considered. to react as a reducing agent towards oxidizing com pounds. While H2SO4 was added to heat with KMnO4, MnO2, Ce(SO4)2, CeO2, K2Cr2O7, CrO3, NH4VO3 and V2O5, and then (NH4)2S2O8 was added, they were recognized to be reduced. Therefore, if (NH4)2S2O8 is used as an oxidizing agent, it should be heated after it is added at room temperature, however, in order to use it as a reducing agent, it should be added after it is heated.
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Valency
Reducing agent
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Complex Properties of Black Wattle Extract and Its Oxidizing Modified Products Reacting With Cr(III)
Complex reactions between Cr 3+ and Black Wattle Extract and its oxidizing degraded products (obtained by using 15%,30%and 60% H 2O 2)have been studied and variations of pH and precipitate in these reactions ave also been determined. The results show that(1)The oxidizing degraded products have different complex properties from original extract, and vary with oxidizing degree.(2) The complexes of high oxidizing degraded products with Cr(Ⅲ) have no precipitate in pH 2-12,and they can resist certain alkali; While the complexes of moderate oxidizing degraded products have precipitate, and precipitate rises correspondingly with temperature rises, and varies with different products.(3)Under the same temperature,pH rises with the increase of usage in extract products, and the higher the oxidizing degree of products, the higher pH rises.
Oxidizing agent
Wattle (construction)
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Molecular oxygen
Oxygen evolution
Oxygen-evolving complex
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Abstract Carboxylic functionalized β ‐carbolines were successfully synthesized in good to excellent yields and high selectivity under mild conditions by aerobic oxidation in the presence of NHPI and transition metal salt using molecular oxygen as an oxidizing agent. A variety of derivatives of fascaplysin thus are available for structure‐bioactivity investigations.
Oxidizing agent
Molecular oxygen
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Oxygen evolution
Oxygen-evolving complex
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Oxidizing agent
Primary (astronomy)
Alcohol Oxidation
Molecular oxygen
Tertiary alcohols
Primary alcohol
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An efficient and simple catalytic system based on RuCl3 dissolved in ionic liquids has been developed for the oxidation of alcohols into aldehydes and ketones under mild conditions. A new fluorinated ionic liquid, 1-n-butyl-3-methylimidazolium pentadecafluorooctanoate, was synthesized and demonstrated better performance that the other ionic liquids employed. Moreover this catalytic system utilizes molecular oxygen as an oxidizing agent, producing water as the only by-product.
Oxidizing agent
Alcohol Oxidation
Molecular oxygen
Catalytic Oxidation
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