Solubility of Substituted Aromatic Hydrocarbons in Supercritical Difluoromethane

Abbott, Andrew P.; Corr, Stuart J.; Durling, and Nicola E.; Hope, Eric G.

doi:10.1021/je0155397

Cited by 33 publications

(37 citation statements)

References 15 publications

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“…[36] Hence, the same technique should be suitable to follow changes in solute concentration during a reaction. Dielectrometry is a rapid, in situ method for measuring capacitance changes of a medium and has the advantages that it is not affected by high solute concentration, high pressure and turbidity constraints that are present with many spectroscopic techniques.…”

Section: Results and Discussion Rate Law Of The Friedel-crafts Alkylamentioning

confidence: 99%

“…[35,36] CH 2 F 2 (Ineos Fluor 99.99 %) and CO 2 (BOC 99.9 %) were used as received. The Friedel-Crafts alkylation of anisole (Aldrich, 99 %) and toluene (Fisher, 98 %) using 2-methyl-2-propanol (tert-butanol) (Aldrich, 99.5 %) or 2-chloro-2-methylpropane (tert-butylchloride) (BDH, 99 %) was carried out with p-toluenesulfonic acid monohydrate (Lancaster, 98 %) as the acid catalyst.…”

Section: Methodsmentioning

confidence: 99%

“…The conversion was calculated using the procedure described previously. [36] A calibration curve was produced which showed a linear correlation between capacitance and product yield. The products were trapped by depressurization into a larger volume autoclave, which also stopped the reaction and the products were analyzed by gas chromatography/mass spectrometry (GC-MS; Perkin Elmer).…”

Section: Methodsmentioning

confidence: 99%

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Pressure Effects on Friedel–Crafts Alkylation Reactions in Supercritical Difluoromethane

et al. 2005

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Dielectrometry is used as a novel technique for following the rate of a Friedel-Crafts alkylation reaction in supercritical (sc) difluoromethane. Although the process was not optimized, good product yields were obtained and reaction rates were found to be larger than in CO2 at comparable conditions. The reaction order is determined using the initial rate method and the reaction is shown to be first-order with respect to both anisole and t-butyl chloride. The reaction rate constant is unaffected by pressures above 120 bar but close to the critical pressure the value decreases with increasing pressure. It is also shown that the product distribution for the alkylation of anisole shows significant pressure dependence with substitution at the ortho-position being favored at lower pressures, which is ascribed to hydrogen bonding. This pressure dependency is not observed in sc CO2 or using toluene as a substrate, which supports the idea that hydrogen bonding may be important in the reaction mechanism. The effect of the different reagents and temperature on the rate of the alkylation reaction was also determined.

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Section: Results and Discussion Rate Law Of The Friedel-crafts Alkylamentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Pressure Effects on Friedel–Crafts Alkylation Reactions in Supercritical Difluoromethane

et al. 2005

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“…Special attention is directed to high temperature electrochemistry 12, 166, 192 and to electrochemistry in subcritical and supercritical fluids. 193–263 Modern thermoelectrochemistry is considered in the chapters dealing with non‐isothermal cells 264–446. In these chapters, all the papers are discussed that contributed substantially to the formation of a new approach resulting in modern thermoelectrochemistry, that is, to the subject outlined in this review.…”

Section: Introductionmentioning

confidence: 99%

Participation of the liver gluconeogenesis in the glibenclamide‐induced hypoglycaemia in rats

Geisler

Felisberto-Junior

Tavoni

et al. 2011

Cell Biochemistry & Function

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We previously demonstrated an increased liver gluconeogenesis (LG) during insulin-induced hypoglycaemia. Thus, an expected effect of sulphonylureas induced hypoglycaemia (SIH) could be the activation of LG. However, sulphonylureas infused directly in to the liver inhibits LG. Considering these opposite effects we investigated herein LG in rats submitted to SIH. For this purpose, 24 h fasted rats that received glibenclamide (10 mg kg(-1) ) were used (SIH group). Control group received oral saline. Glycaemia at 30, 60, 90, 120 and 150 min after oral administration of glibenclamide were evaluated. Since the lowest glycaemia was obtained 120 min after glibenclamide administration, this time was chosen to investigate LG in situ perfused livers. The gluconeogenesis from precursors that enters in this metabolic pathway before the mitochondrial step, i.e. L-alanine (5 mM), L-lactate (2 mM), pyruvate (5 mM) and L-glutamine were decreased (p < 0·05). However, the gluconeogenic activity using glycerol (2 mM), which enters in the gluconeogenesis after the mitochondrial step was maintained. Taken together, the results suggest that the inhibition of LG promoted by SIH overcome the activation of this metabolic pathway promoted by IIH and could be attributed, at least in part, to its effect on mitochondrial function.

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“…[15][16][17][18] The polar properties of HFC make them efficient extraction solvents either on their own or in conjunction with CO 2 or other nonpolar solvents. At present only a small number of such polar fluids 19,20 have been studied, including CF 3 H and CCl 3 F. Owing to their low toxicity and nonflammability, alternative hydrofluorocarbon (HFC) propellants would be desirable.…”

Section: Introductionmentioning

confidence: 99%

Phase Behaviors of Aerosol-OT Analogue Fluorinated Surfactants in 1,1,1,2-Tetrafluoroethane and Supercritical CO₂

Liu

et al. 2006

Ind. Eng. Chem. Res.

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A series of Aerosol-OT (AOT, sodium bis(2-ethylhexyl)sulfosuccinate) analogue fluorinated surfactants, i.e., the sodium salt of bis(2,2,3,3,3-pentafluoropropyl) 2-sulfosuccinate (di-CF2), the sodium salt of bis(2,2,3,4,4,4-hexafluorobutyl)2-sulfosuccinate (di-HCF3), the sodium salt of bis(3,3,4,4,5,5,6,6,6-nonafluorohexyl)2-sulfosuccinate (di-HCF4), and the sodium salt of bis(2,2,3,3-tetrafluoropropyl) 2-sulfosuccinate (di-HCF2), were synthesized and characterized by 1 H NMR, 13 C NMR, 19 F NMR, melting point, and elemental analysis. The pressure-temperature (P-T) phase diagrams for water-in-CO 2 (W/CO 2 ) and water-in-1,1,1,2-tetrafluoroethane (W/HFC-134a) microemulsions stabilized by the surfactants were determined. In this work, the phase behaviors for different surfactants are obtained in supercritical CO 2 (scCO 2 ) and 1,1,1,2-tetrafluoroethane (HFC-134a) as a function of temperature, pressure, and water-to-surfactant ratio. At a fixed temperature, the cloud-point pressures increased with the increase of water-to-surfactant ratio (W o ) and the concentration of the surfactants. The cloud-point pressures for the surfactants in HFC-134a decrease with an increase in temperature at a fixed W o and a surfactant concentration, which is in opposition to the results obtained in scCO 2 .

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Solubility of Substituted Aromatic Hydrocarbons in Supercritical Difluoromethane

Cited by 33 publications

References 15 publications

Pressure Effects on Friedel–Crafts Alkylation Reactions in Supercritical Difluoromethane

Pressure Effects on Friedel–Crafts Alkylation Reactions in Supercritical Difluoromethane

Participation of the liver gluconeogenesis in the glibenclamide‐induced hypoglycaemia in rats

Phase Behaviors of Aerosol-OT Analogue Fluorinated Surfactants in 1,1,1,2-Tetrafluoroethane and Supercritical CO₂

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Solubility of Substituted Aromatic Hydrocarbons in Supercritical Difluoromethane

Cited by 33 publications

References 15 publications

Pressure Effects on Friedel–Crafts Alkylation Reactions in Supercritical Difluoromethane

Pressure Effects on Friedel–Crafts Alkylation Reactions in Supercritical Difluoromethane

Participation of the liver gluconeogenesis in the glibenclamide‐induced hypoglycaemia in rats

Phase Behaviors of Aerosol-OT Analogue Fluorinated Surfactants in 1,1,1,2-Tetrafluoroethane and Supercritical CO2

Contact Info

Product

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About

Phase Behaviors of Aerosol-OT Analogue Fluorinated Surfactants in 1,1,1,2-Tetrafluoroethane and Supercritical CO₂