Sodium Bismuthate as an Oxidizing Agent for Organic Compounds

Nature ◽  
1949 ◽  
Vol 164 (4161) ◽  
pp. 185-186 ◽  
Author(s):  
W. RIGBY
Keyword(s):  
Organic Compounds ◽  
Oxidizing Agent ◽  
Sodium Bismuthate

2, 4-Ionene Supported Permanganate: A Novel, Efficient and Selective Solid Phase Oxidizing Agent for Oxidation of Organic Compounds

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Moslem Mansour Lakouraj ◽  
Sayed Maysam Hossaini ◽  
Vahid Hasantabar ◽  
Masoomeh Soleimani
Keyword(s):  
Aqueous Solution ◽  
Organic Compounds ◽  
Carbonyl Compounds ◽  
Room Temperature ◽  
Solid Phase ◽  
Oxidizing Agent ◽  
Solvent Free Conditions ◽  
Oxidation Of Organic Compounds ◽  
Different Types ◽  
Hydroxyl Compounds

Abstract2, 4-ionene supported permanganate is easily prepared by treatment of 2, 4-ionene with an aqueous solution of potassium permanganate. This reagent could be used as a stable, mild and efficient oxidizing agent to produce carbonyl compounds from hydroxyl compounds or arenes, and disulfides from thiols in either heterogonous or solvent free conditions. In addition, aromatization of different types of 2-arylimidazolines and 2-alkylimidazolines to corresponding imidazoles was achieved in good yields in acetonitrile at room temperature.

Studies of the Vulcanization of Rubber

1952 ◽  
Vol 25 (2) ◽  
pp. 209-229 ◽  
Author(s):  
Shu Kambara ◽  
Kumakazu Ohkita
Keyword(s):  
Organic Compounds ◽  
Chemical Structure ◽  
Room Temperature ◽  
Great Influence ◽  
Cross Linking ◽  
Oxidizing Agent ◽  
Vulcanized Rubber ◽  
Cross Linkage ◽  
Bridge Type ◽  
The Difference

Abstract In this study much information about the method of distinguishing the state in which sulfur is combined in simple organic compounds consisting of carbon, hydrogen, and sulfur was obtained, and a new theory of vulcanization was postulated as a result of its application to vulcanized rubber. When activated sulfur reacts with rubber, it first adds to the double bonds, forming thioketones, which in turn, as a characteristic of these radicals, combine with each other, with the formation of a thioether structure. This transformation of thioketone into thioether takes place, not only during vulcanization, but also gradually after vulcanization. Because of the presence of thioketone, treatment of vulcanized rubber with hydrazine, forms a new network, that is, a ketoazine cross-linkage. Combined sulfur of the thioketone type was determined by an oxidizing agent, and as the difference of this value and total combined sulfur a method of determining bridge type of combined sulfur has been proposed. By this method, it was found that, even in ebonite, about one-third of the combined sulfur is the thioketone type, and that the bridge type is only about two-thirds of the total. The thioketone type of combined sulfur in soft vulcanized rubber is transformed gradually into the thioether type of cross-linkage when allowed to stand at room temperature, and this transformation is accelerated when the temperature is raised. In the case of hard rubber, this phenomenon is also observable, but the rate of this transformation is much slower compared to the former. This tendency is the same in the case of ketoazine cross-linking when rubber vulcanizates are treated with hydrazine. From these facts, it seems that the distribution of the thioketone radicals is not uniform, and the magnitude of the probability for collision of these radicals to form cross-linkages has a great influence on the properties of rubber after vulcanization. That is, the property of the vulcanizate is greatly affected by the fact whether the thioketone radicals in the vulcanizates are comparatively uniformly distributed or whether they exist in sectional groups or in colonies. The authors are the first to advance this postulate concerning the chemical structure of vulcanized rubber and its transformation. We believe that when the study is extended, using this postulation, problems such as aging and the differences in the properties of vulcanized rubber accelerated with various accelerators will become clear. Moreover, we believe that it will be of interest to physicists studying rubber elasticity to suggest this idea of colony of cross-linkages. We are now carrying on researches on these problems, and we shall report on them later.

scholarly journals Modified polyacrylamide supported chlorochromate as a new polymeric oxidizing agent

2012 ◽  
Vol 77 (5) ◽  
pp. 685-697
Author(s):  
Bahman Tamami ◽  
Roghaye Heiran ◽  
Riazi Montazer
Keyword(s):  
Carboxylic Acids ◽  
Organic Compounds ◽  
Oxidation Reaction ◽  
Reaction Times ◽  
Oxidizing Agent ◽  
Polymeric Support ◽  
Chromium Vi ◽  
Hydroxyl Compounds ◽  
Work Up ◽  
Modified Polyacrylamide

Modified polyacrylamide supported chlorochromate was synthesized and used as a versatile and efficient oxidizing agent for the oxidation of various organic compounds such as hydroxyl compounds, silylethers, oximes, thiols, and other compounds. Over oxidation of the products (aldehydes to carboxylic acids) was not observed with this oxidizing agent. The oxidant was insoluble in oxidation media and chromium (VI) ions remained firmly bound to the insoluble polymeric support after the oxidation reaction. The mild reaction condition, easy work-up, short reaction times, regenerability of the reagent and its easy preparation and handling are among the advantages of this new polymeric chlorochromate reagent.

scholarly journals Optimization of parameters applied to degradation and mineralization of p-nitrophenol using advanced oxidative processes

2021 ◽  
Author(s):  
Vanessa Santolin ◽  
Gabriel André Tochetto ◽  
Adriana Dervanoski ◽  
Gean Delise Leal Pasquali
Keyword(s):  
Experimental Data ◽  
Organic Compounds ◽  
Degradation Kinetics ◽  
Oxidizing Agent ◽  
Order Model ◽  
Optimization Of Parameters ◽  
First Order ◽  
No Formation ◽  
Advanced Oxidative Processes ◽  
Oxidative Processes

Abstract Advanced oxidative processes are widely used in the degradation of organic compounds. The degradation and mineralization of the PNF was evaluated by means of an experimental factorial design, using photolysis (UV) and photo-peroxidation (UV/H2O2). With the results optimized, degradation kinetics was performed and the experimental data adjusted to mathematical models. In the UV system, it was possible to degrade just over 65% and mineralize 15% over 7 h of reaction; however, with the addition of the oxidizing agent H2O2, it was possible to obtain 100% removal of the contaminant, suggesting that there was no formation of intermediate compounds. Kinetics results fitting the first order model and the velocity constants revealed that degradation is extremely faster in the UV/H2O2 system (k1,UV/H2O2 = 0.0580 min− 1 > k1,UV = 0.0018 min− 1).

scholarly journals Advanced Oxidation Processes (AOPs) – Utilization of Hydroxyl Radical and Singlet Oxygen

2021 ◽  
Author(s):  
Pavel Krystynik
Keyword(s):  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Organic Compounds ◽  
Organic Contaminants ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Chemical Oxidation ◽  
Oxidizing Agent ◽  
Oxidation Processes ◽  
High Concentrations

Considering the nature of organic contaminants in water, methods of their oxidative decomposition seem to be most appropriate for their removal from contaminated water. There are a lot of methods of chemical oxidation, however, Advanced Oxidation Processes (AOPs) seem to be the most suitable technologies for organic contaminants removal. AOPs belong to a group of processes that efficiently oxidize organic compounds towards harmless inorganic products such as water or carbon dioxide. The processes have shown great potential in treatment of pollutants of low or high concentrations and have found applications for various types of contamination. The hydroxyl radical (•OH) is oxidizing agent used at AOPs to drive contaminant decomposition. It is a powerful, non-selective chemical oxidant, which reacts very rapidly with most organic compounds. Another strong oxidizing agent, singlet oxygen, can be generated by photosensitization of phthalocyanines. Phthalocyanines are molecules based on pyrrol structures connected mainly with methionine groups (–CH=) having a metallic central atom. Illumination upon specific wavelengths initiates formation of singlet oxygen that attack organic contaminants.

The Tempo and mode(S) of Prebiotic Evolution

1997 ◽  
Vol 161 ◽  
pp. 419-429 ◽  
Author(s):  
Antonio Lazcano
Keyword(s):  
Origin Of Life ◽  
Organic Compounds ◽  
Biological Evolution ◽  
Current Evidence ◽  
Early Diversification ◽  
Time Period ◽  
The Galaxy ◽  
History Of ◽  
Widespread Phenomenon ◽  
The Origin Of Life

AbstractDifferent current ideas on the origin of life are critically examined. Comparison of the now fashionable FeS/H2S pyrite-based autotrophic theory of the origin of life with the heterotrophic viewpoint suggest that the later is still the most fertile explanation for the emergence of life. However, the theory of chemical evolution and heterotrophic origins of life requires major updating, which should include the abandonment of the idea that the appearance of life was a slow process involving billions of years. Stability of organic compounds and the genetics of bacteria suggest that the origin and early diversification of life took place in a time period of the order of 10 million years. Current evidence suggest that the abiotic synthesis of organic compounds may be a widespread phenomenon in the Galaxy and may have a deterministic nature. However, the history of the biosphere does not exhibits any obvious trend towards greater complexity or «higher» forms of life. Therefore, the role of contingency in biological evolution should not be understimated in the discussions of the possibilities of life in the Universe.

Triple Fixation For Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 90-91 ◽  
Author(s):  
M. A. Hayat
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Plasma Membrane ◽  
Myelin Sheath ◽  
Good Deal ◽  
Granular Structure ◽  
Oxidizing Agent ◽  
Fixation Technique ◽  
Large Clusters

Potassium permanganate has been successfully employed to study membranous structures such as endoplasmic reticulum, Golgi, plastids, plasma membrane and myelin sheath. Since KMnO4 is a strong oxidizing agent, deposition of manganese or its oxides account for some of the observed contrast in the lipoprotein membranes, but a good deal of it is due to the removal of background proteins either by dehydration agents or by volatalization under the electron beam. Tissues fixed with KMnO4 exhibit somewhat granular structure because of the deposition of large clusters of stain molecules. The gross arrangement of membranes can also be modified. Since the aim of a good fixation technique is to preserve satisfactorily the cell as a whole and not the best preservation of only a small part of it, a combination of a mixture of glutaraldehyde and acrolein to obtain general preservation and KMnO4 to enhance contrast was employed to fix plant embryos, green algae and fungi.

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