Biphasic Reaction (biphasic + reaction)

Distribution by Scientific Domains
Chemistry60%

Selected Abstracts

Insights into the Role of the Liquid,Liquid Interface in Biphasic Reactions: The Reaction of Vitamin B12s(aq) with Vicinal Dibromides(oil)

CHEMPHYSCHEM, Issue 12 2005
Trevor J. Davies Dr.
Abstract Electrocatalytic processes can take place either homogeneously in a single liquid phase or heterogeneously at the liquid,liquid interface formed in emulsions. This Article addresses the question as to whether a change in rate and/or mechanism can occur between the two possibilities. Specifically, cyclic voltammetry and electrosynthetic experiments are used to demonstrate that for the vitamin B12 mediated reduction of vicinal dibromides producing olefins, electric field effects likely operate at the liquid,liquid interface which can change the populations of different conformers relative to the single homogeneous-phase experiment, leading to significant changes in rate. [source]

Development of a Supported Ionic Liquid Phase (SILP) Catalyst for Slurry-Phase Friedel,Crafts Alkylations of Cumene

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009
J. Joni
Abstract A supported ionic liquid phase (SILP) catalyst material has been developed based on a silica support coated with an acidic chloroaluminate ionic liquid. Compared to the results in a liquid-liquid biphasic reaction these materials showed in the isopropylation of cumene a clearly different selectivity which was found to be related to a reduction of the ionic liquid's acidity by the untreated silica support. By pretreating the support with a defined amount of ionic liquid for neutralization and removal of surface hydroxy groups, a well defined, very active and also very selective SILP catalyst for slurry phase Friedel,Crafts alkylation was obtained. [source]

Dramatic Pressure Effects on the Selectivity of the Aqueous/Organic Biphasic Hydrogenation of trans -Cinnamaldehyde Catalyzed by Water-Soluble Ru(II)-Tertiary Phosphane Complexes

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2003
Gábor Papp
Abstract In a water/chlorobenzene biphasic reaction, the hydrogenation of trans- cinnamaldehyde, catalyzed by water-soluble Ru(II)-phosphane complexes at pH,3.04 (phosphate buffer), produces a 61:39 mixture of cinnamyl alcohol and dihydrocinnamaldehyde at 1,bar H2; however, the selectivity is increased to 93:7 by increasing the hydrogen pressure to 8,bar. [source]

Degranulation of Mast Cells Provokes a Massive Inflammatory Reaction in the Tympanic Membrane,

THE LARYNGOSCOPE, Issue 7 2001
Per Olof Eriksson MD
Abstract Objective The pars flaccida is extremely rich in mast cells. On stimulation the mast cells release preformed and de novo synthesized inflammatory substances. The purpose of this study was to examine how these mast cell substances provoke inflammatory changes in the tympanic membrane. Study Design In vivo, murine model. Methods In a rat model, the mast cell secretagogue compound 48/80 was applied locally to the tympanic membrane on 4 consecutive days and the ensuing inflammatory changes were evaluated by otological, light, and electron microscopy 3, 6, 9, 12, 18, 24, 36, and 48 hours and 4, 6, and 8 days later. Results Degranulation of the mast cells occurred within 3 hours of applying compound 48/80. Release of the mast cell substances coincided with an inflammatory event characterized by a two-stage reaction: an edema stage, peaking 6 hours after application, followed by a massive invasion of inflammatory cells, peaking at 24 and 48 hours. Pars flaccida and pars tensa were both involved, pars flaccida showing the earliest changes. Pars tensa exhibited the same biphasic reaction as pars flaccida, but approximately 6 hours later. Conclusions The mast cells of the pars flaccida have the capacity to elicit an intense inflammation of the tympanic membrane. The biphasic reaction pattern resembles that observed in experimental otitis media, suggesting involvement of the mast cells in this inflammatory condition of the middle ear. [source]

Microbial desulfurization of gasoline by free whole-cells of Rhodococcus erythropolis XP

FEMS MICROBIOLOGY LETTERS, Issue 2 2006
Bo Yu
Abstract Rhodococcus erythropolis XP could grow well with condensed thiophenes, mono-thiophenic compounds and mercaptans present in gasoline. Rhodococcus erythropolis XP was also capable of efficiently degrading the condensed thiophenes in resting cell as well as biphasic reactions in which n -octane served as a model oil phase. Free whole cells of R. erythropolis XP were adopted to desulfurize fluid catalytic cracking (FCC) and straight-run (SR) gasoline oils. About 30% of the sulfur content of FCC gasoline and 85% of sulfur in SR gasoline were reduced, respectively. Gas chromatography analysis with atomic emission detection also showed depletion of sulfur compounds in SR gasoline. Rhodococcus erythropolis XP could partly resist the toxicity of gasoline and had an application potential to biodesulfurization of gasoline. [source]