Modified Wittig Reactions Using Triethylamine and Lithium Halides: Synthesis of α,β-Unsaturated Esters from Ketones and Ethyl Bis(Trifluoroethyl)Phosphonoacetate

A modified HWE reaction using triethylamine and lithium bromide with ethyl bis(trifluoroethyl)phosphonoacetate gives satisfactory yields of α,β-unsaturated esters from a variety of ketones.     

A Convenient Procedure for the Preparation of Reactive Zinc for the Reformatsky Reaction

A reactive zinc powder is obtained by addition of ZnCl₂ to a lithium dispersion suspended in ether. Reformatsky Reactions with the zinc powder are described.     

On the global existence of weak solution for a multiphasic incompressible fluid model with Korteweg stress

In this paper, we study a multiphasic incompressible fluid model, called the Kazhikhov–Smagulov model, with a particular viscous stress tensor, introduced by Bresch and co‐authors, and a specific diffusive interface term introduced for the first time by Korteweg in 1901. We prove that this model is globally well posed in a 3D bounded domain. Copyright © 2016 John Wiley & Sons, Ltd.     

Adhesion Probability of Colloidal Particles with Repulsive Soft Interaction

Computer simulations of the irreversible adhesion of charged colloidal particles at a solid/liquid interface are performed to determine whether the distribution of particles in the vicinity of a preadsorbed (also charged) one follows the Boltzmann law applied to ana prioriuniform adhesion probability, as first assumed by Adamczyket al.(J. Colloid Interface Sci.140, 123 (1990)). If true, this would indicate that the whole information on the deposition process is contained in the potential energy distribution on the adsorbing surface. In general, diffusion in a field of force and the irreversibility of the process induce significant deviations from the Boltzmann-weighted uniform adhesion density. Nevertheless, it is shown that for particles characterized by a small gravitational energy this procedure leads to a reasonable first approximation of the distribution of the particles over the adsorbing surface. This observation thus demonstrates the validity of Adamczyk's assumption and extends its range of applicability to the case of a weak gravitational field.     

Etude du fluorure de propargyle par RMN en phase nematique: Determination de la geometrie moleculaire et des signes des differentes constantes de couplage indirect

NMR spectra of proton, fluorine-19 and carbon-13 satellites of partially oriented propargyl fluoride have enabled the complete structure of this molecule to be determined. Agreement with microwave results is excellent, except for the carbon-fluorine bond length. Signs of all indirect coupling constants have been determined.     

Structure du propyne par RMN en phase nématique. Utilisation des satellites du carbone-13

The proton NMR spectrum and carbon-13 satellites of partially oriented propyne give the complete structure of this molecule. Agreement with microwave results is excellent.     

Structural,Textural and Mechanical Properties of Products Obtained by Interaction of Metakaolin-phosphoric Acid at High Temperature

Russian Journal of Applied Chemistry - The various molar ratios of P/Si + Al (0.1, 0.2, 0.4, and 1.4), based on metakaolin and phosphoric acid, have been investigated at two temperatures 750 and...     

Isomerisation Catalysee Par le Gel de Silice et L'argile Activee de N-Acyl-2,2-Dimethylaziridines: Approche Mecanistique

Silica gel and activated clay, behaving as Lewis acids, reacted with N-acyl-2,2-dimethylaziridines 1 to lead to pentacoordinated aziridinium silicate ions. The regiospecific ring opening on the CMe₂ carbon side of the intermediate I involves, after removal of the catalyst, the zwitterion II. The zwitterion II undergoes either a transfer of proton leading to the N-methallylamide 2 or intramolecular cyclization reaction leading to the oxazoline 3. The unstable oxazoline 3 on catalyst is hydrated in turn into amidoalcohol 4 via the oxazolinium silicate III.     

Evaluation of phosphate removal from water by calcined-LDH synthesized from the dolomite

In the present study, the characteristics of the adsorption of phosphate on calcined layered double hydroxides (LDHs) from aqueous solution were evaluated under laboratory conditions. The anionic clays were Mg₃pH₁₀-LDH synthesized by co-precipitation and D ₁pH₁₀-LDH synthesized from the dolomite. The equilibrium isotherm showed that the uptake of phosphate ion by Mg₃pH₁₀(500)-LDH was in agreement with the Langmuir and Freundlich equations; the Langmuir model gave a better fit to the experimental data than the Freundlich one. The equilibrium isotherm showed, however, that the adsorption of the phosphate on D₁pH₁₀(500)-LDH was accompanied with precipitation reac tion of the phosphate salts. A mechanism proposed for the removal of phosphate ion has been confirmed by X-ray diffraction and FT-IR spectroscopy.