Synthese de derives mono- et bicycliques du bore tetracoordonne et des α-aminodiacides

Triethyl- and triphenyl-boranes react with α-aminodiacids, R¹N(CHR²COOH)₂ (R¹ = H, Me, PhCH₂; R₂ = H, Me), leading to mono- and bi-cyclic compounds. Depending on the experimental conditions and the substitution of the aminodiacid, either can be isolated. Eight compounds were prepared.     

Les α et β-Cetophosphonates,des Precurseurs de Pyrrolidines et de Quinoleines Phosphonatees

The condensation of primary amines on α- or β-ketophosphonates affords the corresponding iminophosphonates. The reaction was found to be highly stereoselective, affording the E isomer exclusively. These phosphonylimines were then treated in basic media to give pyrrolidines and quinolines through intramolecular cyclization. The structures of all obtained products were confirmed by NMR spectroscopy (¹H, ³¹P, ¹³C), and in some cases by mass spectrometry.     

Analyse spectrale des poudres non conductrices,et en particulier de la silice et des silicates par émission ultraviolette et absorption infra-rouge

Résumé Cette communication a pour but de présenter les applications analytiques faites au laboratoire de spectrographie du Centre d'études et recherches des charbonnages de France pour la résolution des problèmes posés par les chercheurs du Centre ou des Houillères.Des analyses d'émission UV permettent le contrôle de la pureté des poudres utilisées en tests animaux, la composition des cendres de charbon, schistes etc. L'utilisation systématique de la technique du pastillage des poudres fines avec du bromure de potassium permet leur étude en IR de 2 à 15 microns: dosage du quartz, de la calcite etc. Nous montrons également une application de l'absorption UV à l'étude des acides siliciques de préparation variée.

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Summary The object of this communication is to present the analytical applications made in the spectrographic laboratory of the Centre d'études et recherches des charbonnages de France for the resolution of the problems posed by the investigators of the Centre or of the collieries.Some ultraviolet emission analyses permit the control of the purity of powders used in animal tests, the composition of coal ashes, schists, etc. The systematic use of the tabletting of fine powders with potassium bromide allows their investigation in infrared from 2 to 15 microns: determination of quartz, calcite, etc. The autors also demonstrate an application of the ultraviolet absorption to the study of silicic acids of varied preparation.

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Zusammenfassung Es wird über die Anwendung der im spektrographischen Laboratorium des Centre d'études et recherches des charbonnages de France verwendeten Methoden zur Bearbeitung der seitens der Wissenschaftler des Instituts oder der Gruben gestellten Fragen berichtet. Unter Verwendung der UV-Emissionspektralanalyse ist es möglich, die Reinheit im Tierversuche benutzter Pulver zu prüfen, wie auch die prozentuale Zusammensetzung von Kohlenaschen, der Berge usw. zu bestimmen. Für die Untersuchung von feinen Pulvern mittels IR-Spektroskopie zwischen 2 und 15 wird die Technik der Brikettierung der Probe mit Kaliumbromid systematisch benutzt (Bestimmung von Quarz, Kalkspat...). Auch die Anwendung der UV-Absorption zur Untersuchung von Kieselsäuren verschiedener Herkunft wird beschrieben.

     

Spectres de rmn et analyse conformationnelle des méthyl-2 et benzyl-2 indanones-1 et de leurs complexés chrome tricarbonyle

Nuclear magnetic resonance spectra of 2-methyl 1-indanon, 2-benzyl 1-indanon and their chromium tricarbonyl complexes have been completely analysed. Magnetic nonequivalence of the two aliphatic protons of the benzylic chain gives informations about conformation of the benzyl group.     

Synthese et Etude Conformationnelle Par RMN (1H, 13C, 31P) et DFT des Cycloalcoxyphosphinallenes et des Hydrazones β-Cycloalcoxyphosphonatees

Abstract

The addition of hydrazine and its derivatives to cycloalkoxyphosphinallenes leads to β-(5,5-dialkyl-2-oxo-1,3,2-dioxaphosphoranyl)-hydrazones in good yields. The structure of the obtained compounds were elucidated by the NMR (¹H, ¹³C, ³¹P) spectroscopy and density functional theory (DFT) calculations at B3LYP/6-311++G (2d, 2p) level of theory.     

Synthese et reactivite des perfluoroalkyl-3 alkylthio-3 propenoates d'ethyle: thiophenes et β-thioxoesters perfluoroalkyles

The action of thiols with perfluoroalkylated α,β,-unsaturated compounds (ethyl 3-F-alkyl propynoates 1 and ethyl 3-F-alkyl propenoates 2) was investigated and the reactivity of the adducts reported. The mono-adducts Z and E formed by the action of thiols with 1 were unambiguously identified by ¹⁹F-NMR. In addition to the expected alkenes Z and E, the reaction of 1 with ethyl mercaptoacetate led to ethyl 2-F-alkyl-4-hydroxy-3-thiophenecarboxylate 7. The cyclisation of ethyl 3-F-alkyl-3-(methoxycarbonylmethylthio) propenoate Z in basic medium afforded methyl 5-F-alkyl-3-hydroxy-2-thiophenecar-boxylate 8, whereas in similar conditions ethyl 3-F-alkyl-3-(methoxycarbonylethylthio)propenoate led to ethyl 3-F-alkyl-3-mercaptopropenoate as a first example of β-thioxoesters bearing a sulfur atom on the α-carbon of the perfluoroalkylated chain.     

Effet Josephson et expérience d'Andronikashvili

A way of making a weak link in superfluid helium 4 is proposed. Putting this weak link in a torsion pendulum of the Andronikashvili type adds high frequency vibrations to the regular oscillations. We also propose a schema of SQUIDac type for a gyroscope.     

Transformations intégrales et identification modale

This note deals with modal identification of linear structures from their responses to vibration tests. The aim of the proposed method is to allow direct identification of the Frequency Response Function from the computation of an integral transform. Theoretically, this integral transform can be written in three different ways depending on the studied domain (time, frequency, or Laplace domain). The introduction of a integer parameter in the transform facilitates the identification of the modal parameter, especially when the system has neighboring poles in the complex plane. The efficiency of the proposed method is tested in the case of a discrete system with three degrees of freedom and whose poles are neighboring.     

Les piles à combustible et leurs applications

Fuel cells and their applications. Fuel cells have been developed for many years. During the sixties they were developed for various applications but were first only manufactured for space applications, for price reasons. A lot of work has been performed, basic and applied, to improve and introduce these electrochemical power sources in everyday life. Phosphoric Acid Fuel Cells (PAFCs) were then developed and marketed for stationary applications, while Polymer Electrolyte Membrane Fuel Cells (PEMFCs) are now becoming an interesting solution for mobile applications, due to the possibility of a high power density.     

Sous-structuration dynamique et calcul parallèle

Iterative substructuring methods and parallel computing allow one to develop new implementations of the modal synthesis method proposed by Craig and Bampton enabling one to consider and solve large-scale problems.     

Arylhydrogermyllithiums: synthèse et applications

New organohydrogermyllithium are prepared in good yields from hydrogermolysis reactions with t-butyllithium in THF. Alkylatioin and germylation of the germaniumlithium bond in these compounds are efficient reactions and a convenient way for synthesis of organohydropolygermanes. These reagents are also useful for the formation of unknown hydrogermylmagnesium compounds     

Fractionneur automatique a siphon forme et caractéristiques des siphons pour liquides polaires et liquides non-polaires

The shape, characteristics and conditions of working of the syphons that ensure the most efficient fractionating by means of automatic fraction collectors have been investigated. The liquid deliveries to the syphon must be sufficiently slow. With solvents having a low surface tension, the inside diameter of the upper elbow must not be greater than a given value. It is essential that the inside diameter of the lower elbow should become regularly narrower from the inlet tube to the outlet tube. The volume of the liquid remaining in the syphon immediately after draining is smallest for a given diameter of the inlet tube and of the outlet tube, and for a proper radius of the lower elbow. The good working of the syphon depends upon the balance between those various factors that often come into play in opposite ways.Then, from these data, a syphon has been made equipped with a ball float that makes possible the use of non-polar liquids in the automatic fraction collectors electrically controlled.     

Etude de la structure des hydroxydes de gallium et d'indium par thermogravimétrie et absorption infrarouge

Zusammenfassung Der Vergleich der Absorptionsspektren von GaOOH und In(OH)₃ im IR zwischen 1 und 30 mit Spektren von Kristallen des gleichen Typus läßt die Valenz- und Deformationsschwingungen der Hydroxylgruppen erkennen.

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Summary Comparison of the infrared absorption spectra, between 1 and 30, of GaOOH and In(OH)₃ with those of crystals of the same type gave evidence of valence vibrations and deformation of the OH groups.

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Résumé La comparaison des spectres d'absorption infrarouge entre 1 et 30 de GaOOH et de In(OH)₃ avec ceux de cristaux de même type, met en évidence les vibrations de valence et de déformation des groupements OH.

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En l'honneur du Prof.A. A. Benedetti-Pichler, respectueusement.     

Sur une combinaison borotartrique et son application à la recherche et au dosage microchimiques de l'ion borique

Summary In the presence of tartaric acid, borate reacts with barium to produce a precipitate of constant composition and very low water-solubility. The analysis of this presumably complex barium borotartrate yields to empirical formula Ba₅B₂C₁₂H₈O₂₄ · 4 H₂O. The qualitative detection of boron by means of this characteristic precipitate has a limiting concentration of 10^–5. A method is described for the gravimetric determination of boron on the semimicro scale, and also a volumetric method for the micro-determination of boron, which employs the iodometric measurement of barium as chromate, where 1 ml of 0,01 N thiosulfate solution corresponds to 14,4 B. The principle of this method can be also applied to complex inorganic, organic or biological solutions, after ashing.

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Zusammenfassung Bei Gegenwart von Weinsäure läßt sich Borat mit Barium in Form eines Niederschlages konstanter Zusammensetzung (wahrscheinlich als komplexes Bariumborotartrat) und sehr geringer Wasserlöslichkeit fällen, dessen Analyse der Formel Ba₅B₂C₁₂H₈O₂₄ · 4 H₂O entspricht. Der qualitative Bornachweis ist mit Hilfe dieser charakteristisch geformten Fällung bis zu einer Grenzkonzentration von 10^–5 zu führen. Ein Verfahren zur gravimetrischen Borbestimmung im Halbmikromaßstab und eine Methode zur volumetrischen Mikrobestimmung des Bors über die jodometrische Erfassung des Bariums als Chromat wird angegeben, wobei 1 ml 0,01-n-Thiosulfatlösung 14,4 B entspricht. Das Prinzip dieser Methode läßt sich auch auf komplexe anorganische, organische bzw. biologische Lösungen nach deren Veraschung anwenden.

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Avec 1 figure.     

Analyse vibrationnelle infrarouge et Raman du benzosélénophène et du benzotellurophène

Infrared (4000-200 cm⁻¹; vapour solid and solution dissolved in inert and proton acceptor solvents) Raman (4000-100 cm⁻¹, solid and solution) spectra of benzoselenophene and benzotellurophene have been recorded. A complete attribution of the fundamental vibrations is proposed. The fundamental vibration wavenumbers evolution for a series of monoheteroatomic benzoheterocycles C₈H₆X with X = O, S, Se and Te is analysed.