Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry最新文献_第9页

Sulfanyl radical addition–cyclization and its synthetic application 磺酰自由基加成-环化及其合成应用

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-06-01 DOI: 10.1016/S1387-1609(01)01256-7

Okiko Miyata, Takeaki Naito

引用次数: 1

Formal total synthesis of (±)-bisabolangelone by using a radical cyclization 用自由基环化法正式合成(±)-双abolangelone

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-06-01 DOI: 10.1016/S1387-1609(01)01246-4

Janine Cossy, Véronique Bellosta, Barbara Gille

引用次数: 0

Samarium diiodide-promoted sequential coupling-aldol-reduction reactions of ferrocene-substituted enones 二碘化钐促进二茂铁取代烯酮的序贯偶联醛缩还原反应

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-06-01 DOI: 10.1016/S1387-1609(01)01257-9

Shean-Jeng Jong, Chao-Tsen Chen, Jim-Min Fang, Yi-Hong Liu, Gene-Hsiang Lee, Yu Wang

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引用次数: 2

1,5-Hydrogen atom transfer from α, β and γ carbons to an alkenyl or aryl radical in cycloalkanones 环烷酮中1,5-氢原子从α、β和γ碳转移到烯基或芳基自由基

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-06-01 DOI: 10.1016/S1387-1609(01)01262-2

Chin-Kang Sha, Wen-Yueh Ho, A.K. Mohanakrishnan, Chiu-Ling Lin, San-Yan Chu

引用次数: 0

Experimental study of platinized poly-2,5-dimethoxyaniline electrodes 铂化聚2,5-二甲氧基苯胺电极的实验研究

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-05-01 DOI: 10.1016/S1387-1609(01)01250-6

Lizong Dai , Jean-Yves Gal , Huihuang Wu

{"title":"Experimental study of platinized poly-2,5-dimethoxyaniline electrodes","authors":"Lizong Dai , Jean-Yves Gal , Huihuang Wu","doi":"10.1016/S1387-1609(01)01250-6","DOIUrl":"10.1016/S1387-1609(01)01250-6","url":null,"abstract":"<div>In the domains of chemical catalysis and analytical chemistry, the modification of metal electrodes by the deposition of multilayers was developed about twenty years ago. The purpose of our work was to compare the behavior of an electrode prepared with a substituted polyaniline with that of electrodes regularly used in analytical chemistry: platinum, platinized platinum and glassy carbon. We initially present results obtained with poly-2,5-dimethoxyaniline (PDMAn) on two classic systems: the couple Fe(CN)63–/Fe(CN)64– and the couple O2/OH–. The first example is often studied during training in electrochemistry because of the good results generally obtained. Levich’s equation is effectively well verified. On the other hand, reduction of oxygen and oxidation of OH– ions are always limited by the rate of the electron transfer reactions. It seems to us that the study of the behavior of these two systems with platinum electrodes covered with PDMAn, platinized or not, could be interesting. The oxidation of isopropanol in a weakly acid medium was also investigated. In the field of analytical chemistry, a more detailed study is mandatory before deciding on the possibility of using electrodes modified with films of substituted polyaniline. An electrode, which would not be platinized, does not seem useful; the use of electrodes prepared with platinized polymers deposited on substrates less expensive than platinum, (glassy carbon for example), may be more interesting. It seems that H2O2 formation over a wide domain of potential would be the best result for oxidations and new experiments will be investigated.</div>","PeriodicalId":100305,"journal":{"name":"Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry","volume":"4 5","pages":"Pages 335-343"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1387-1609(01)01250-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79863258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Phosphomolybdic heteropolycompounds as oxidation catalysts. Effect of transition metals as counter-ions 磷钼杂多化合物作为氧化催化剂。过渡金属作为反离子的作用

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-05-01 DOI: 10.1016/S1387-1609(01)01249-X

Catherine Marchal-Roch , Jean-Marc M. Millet

{"title":"Phosphomolybdic heteropolycompounds as oxidation catalysts. Effect of transition metals as counter-ions","authors":"Catherine Marchal-Roch , Jean-Marc M. Millet","doi":"10.1016/S1387-1609(01)01249-X","DOIUrl":"10.1016/S1387-1609(01)01249-X","url":null,"abstract":"<div>Phosphomolybdic compounds were first described as active catalysts in heterogeneous catalytic reactions some twenty-five years ago. Research on these catalysts underwent a huge acceleration when an industrial application in the oxidation of methacrolein to methacrylic acid was reported. They were later developed with success as catalysts for the oxidative dehydrogenation of isobutyric acid into methacrylic acid for which they surpass in many aspects the FePO catalysts. More recently phosphomolybdic catalysts were shown to be very efficient for the oxidation of light alkanes. The structure of these ionic solids with discrete cations and anions can be defined at the molecular level of the heteropolyanion 〚PMo12O40〛3–, this feature makes them attractive for fundamental studies on catalytic reaction mechanism or catalytic site visualization. In the latter case they represent a unique model of a mixed oxide cluster that can be advantageously used to design new catalysts. Starting from the acid H3〚PMo12O40〛 two substitution types leading to important modifications of the catalytic properties are possible: (i) the substitution of protons with counter-cations, (ii) the substitution of molybdenum in the anions. This review addresses the effect of transition metals substituting protons on both catalytic and physicochemical properties. It will focus on the influence of iron, copper and vanadyl directly introduced as counter-cations and that of vanadium initially substituting molybdenum in the anion but which moves out due to a partial rebuilding of the anions under catalytic reaction conditions. These transition metals have important and complex effects and have been widely studied. In both cases alkaline metals substituting protons have been also studied.</div>","PeriodicalId":100305,"journal":{"name":"Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry","volume":"4 5","pages":"Pages 321-329"},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1387-1609(01)01249-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78391213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Caractérisation par émission acoustique de l’adhérence et de l’endommagement d’un revêtement : cas d’un revêtement WC–Co sur acier 用声发射表征涂层的粘附和损伤:以钢上WC - Co涂层为例

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-05-01 DOI: 10.1016/S1387-1609(01)01240-3

Davy Dalmas , Salim Benmedakhene , Caroline Richard , Abdelouahed Laksimi , Gérard Béranger , Thierry Grégoire

引用次数: 15

Étude des structures électroniques de In2O3 pur et dopé avec l’étain 纯In2O3和掺杂锡的电子结构研究

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-05-01 DOI: 10.1016/S1387-1609(01)01242-7

Samir F Matar , Antoine Villesuzanne , Guy Campet , Josik Portier , Youssef Saikali

引用次数: 1

Structure elucidation of benzopyran-2-ol in solution and in solid state following the reduction of coumarin by DIBAL-H DIBAL-H还原香豆素后，苯并吡喃-2-醇在溶液和固体中的结构解析

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-05-01 DOI: 10.1016/S1387-1609(01)01243-9

Yves Jacquot , Bernard Refouvelet , Olivier Blacque , Marek M Kubicki , Alain Xicluna

引用次数: 0

Chiralité quantitative : le modèle des moindres carrés pondérés 定量手性:加权最小二乘模型

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-05-01 DOI: 10.1016/S1387-1609(01)01241-5

Michel Petitjean

引用次数: 6