Etude de la metallation de l'oxyde de diferrocenyl phenyl phosphine

The reaction of n-BuLi with phenyldiferrocenylphosphine oxide yields a mixture of two isomeric dianions. This mixture reacts with Me₃SiCl, Br₂, CO₂, PhCHO and PhCHNPh to give bifunctional products. With CoCl₂, Me₂SiCl₂, Ph₂SiCl₂, Bu₂SnCl₂ and PhCOOEt, the same mixture gives cyclic products. In almost every case each of these compounds is a mixture of two isomers corresponding to the original compound. The characteristic patterns of the PMR spectra are in full agreement with the structures proposed for the isomeric dianions.     

Tautomerie ceto-enolique du triacetylmethane

Keto-enol tautomerism of triacetylmethane in seven solvents has been investigated, both by NMR and by a bromometric method. The keto form was present in all solvents, and particularly in water (43% at 22°C). Kinetics of keto-enol equilibration was studied spectroscopically. Rates for bromination of the keto-form and for keto-enol interconversion were consistent with the same mechanism for the latter reaction. This mechanism is analogous to that already reported for other β-dicarbonyl compounds.     

Nombre de transport et conductivité cationique dans l'oxyde de nickel: NiO

Ionic transport number measurements have been made on single crystals of NiO over the temperature range 900–1300°C and for oxygen partial pressures varying from 10^?8 to 1 atm. At 1000°C and in air, t_Ni ～ 2 × 10^?7. The variation in cationic conductivity as a function of oxygen partial pressure suggests that V′_Ni is the dominant defect at high temperature and low oxygen pressure and that V″_Ni is the dominant defect at low temperature and high oxygen pressure.     

Etude des solutions solides d'oxyde de lithium dans l'oxyde de nickel. II. Influence de la pression d'oxygene et mecanismes d'incorporation

The formation of solid solutions of lithium and nickel oxides, containing more than 2 at Li %, requires the presence of oxygen under a pressure which must exceed 10^?3 torr at 933 K. Solid solutions containing a maximum of 2 at Li % however can be prepared under a reduced pressure of oxygen (< 10^?4 Torr). Mechanisms are proposed to explain, in both cases, the incorporation of lithium ions in the nickel-oxide lattice.     

Forme des cristallites d'oxyde de cadmium produits par decomposition de l'hydroxyde

The structural transformation that occurs in the cadmium hydroxide decomposition reaction has the morphological and crystallographic character of a martensitic transformation. The authors predict the shape of the oxide crystallites produced during the reaction, viz., small platelets developed parallel to the (111) oxide planes. The difficulty in assessing their shape by analysis of X-ray diffraction line profiles is discussed. Electron microscope and X-ray diffraction results are presented and it is shown that the oxide crystallite shape is dependent on whether the precursor is hydroxide or carbonate.     

Preparation de nouveaux difluorodioxophosphates a partir de l’oxyde de difluorure de phosphoryle Partie V. Reactions aur le trioxyde d’uranium

UO₂(PO₂F₂)₂ has been synthesized from the action of P₂O₃F₄ on UO₃ or uranyl nitrate. The monofluorophosphate UO₂(PO₃F) was obtained by thermal decomposition. Infrared and Raman spectroscopic investigation of UO₂(PO₂F₂)₂ suggest a chain structure with oxygen phosphorus-oxygen bridges.     

Etude des solutions solides d'oxyde de lithium dans l'oxyde de nickel. I. proprietes des solutions solides preparees sous pression reduite d'oxygene

Heating mixtures of lithium and nickel oxides at 1073°K under reduced oxygen pressure (<10^?6 Torr) produces the incorporation of lithium ions in the nickel-oxide lattice. The solubility appears to be limited at 1.9 at Li %. From a study of several properties of solid solutions, it is concluded that the incorporation of lithium ions creates and stabilizes anionic vacancies.     

Preparation de nouveaux difluorodioxophosphates a partir de l'oxyde de difluorure de phosphoryle. Partie II. Reactions sur les acides iodique et periodique.

The new compounds IO₂PO₂F₂ and IO₃PO₂F₂ have been prepared by the reaction of iodic and periodic acids on F₂OPOPOF₂. Raman spectra show a dimeric structure for IO₃⁺ ion but a monomeric structure for IO₂⁺ ion.     

Decomposition d'hypobromites prepares par action de l'oxyde de mercure et du brome sur des alcools bicycliques pontes

Hydrobromites of bridged bicyclic alcohols have been decomposed to yield tetrahydrofuran-type ethers as well as fragmentation products. The latter results from the cleavage of the carbon-carbon bond α, β to the hydroxyl group. In the case of 3-hydroxy-3-methyl bicyclo[3.2.1]octane, conjugated ketones and brominated olefins are formed, whereas tetrahydrofuran-type ethers are formed only under different experimental conditions different from those applicable to general cases. The reaction mechanisms have been established. The influence of the various reaction parameters has been studied in order to obtain selectively either tetrahydrofuran-type ethers or a mixture of conjugated ketones and brominated olefins.     

Influence des impuretés sur la conductivité cationique dans l'oxyde de magnesium monocristallin

The measurement of the cationic transport numbers in MgO single crystals has been performed, using the dilatocoulometric method. In the oxygen partial pressure range 1 to 10^?10 atm at temperatures of 1100 to 1300°C the ionic conduction in MgO is extrinsic.     

Etude par thermogravimetrie,analyse thermique differentielle et spectrographie d'absorption infra-rouge de la reaction du peroxyde de sodium sur l'oxyde de Beryllium

Thermogravimetric and differential thermal methods as well as chemical analysis show that sodium peroxide attacks beryllium oxide to form beryllate, apparently in the molecular ratio 1 Na₂O:1 BeO. An unidentified peroxy compound of beryllium is formed at about 165° by the action of the NaO² present in the Na₂O₂ sample; it decomposes between 280 and 310°. IR absorption spectroscopy indicates the presence of Be-O bonds in the sodium beryllate which are different from those in the oxide used.     

Dosage titrimétrique du tributylphósphate,de la di-n-hexylsulfoxyde et de l'oxyde de tri-n-butylphosphine par les acides de lewis avec repérage visuel du terme

Tri-n-butylphosphate, tri-n-butylphosphine oxide and di-n-hexylsulfoxide were titrated with SnCl₄, SnBr₄ and TiCl₄ in anhydrous 1,2-dichloroethane with malachite green or crystal violet as indicator. Best results were obtained when SnCl₄ was used with malachite green as indicator. The accuracy of the method is about 1–2% for complex concentrations greater or equal to 0.05 M at the equivalence point.