Mechanism of formation of Grignard reagents. The rate of reaction of cyclopentyl bromide with magnesium is transport limited in diethyl ether

1980 ◽  
Vol 102 (1) ◽  
pp. 226-231 ◽  
Author(s):  
Harold R. Rogers ◽  
John Deutch ◽  
George M. Whitesides
Keyword(s):  
Diethyl Ether ◽  
Grignard Reagents ◽  
Mechanism Of Formation ◽  
Rate Of Reaction

Mechanism of formation of Grignard reagents. Kinetics of reaction of alkyl halides in diethyl ether with magnesium

1980 ◽  
Vol 102 (1) ◽  
pp. 217-226 ◽  
Author(s):  
Harold R. Rogers ◽  
Craig L. Hill ◽  
Yuzo Fujiwara ◽  
Randall J. Rogers ◽  
H. Lee Mitchell ◽  
...  
Keyword(s):  
Diethyl Ether ◽  
Alkyl Halides ◽  
Grignard Reagents ◽  
Mechanism Of Formation ◽  
Kinetics Of Reaction ◽  
Kinetics Of

The Kinetics and Mechanism of Formation of Calcium Sulfate Scale Minerals—The Influence of Inhibitors

CORROSION ◽  
1979 ◽  
Vol 35 (7) ◽  
pp. 304-308 ◽  
Author(s):  
GEORGE H. NANCOLLAS ◽  
WESLEY WHITE ◽  
FELIX TSAI ◽  
LARRY MAS LOW
Keyword(s):  
Calcium Sulfate ◽  
Mechanism Of Formation ◽  
Seeded Growth ◽  
Langmuir Adsorption ◽  
Calcium Sulfate Dihydrate ◽  
Calcium Sulfate Scale ◽  
Rate Of Reaction ◽  
Growth Method ◽  
Kinetics Of ◽  
Calcium Sulfate Hemihydrate

Abstract A seeded growth method has been used to study the kinetics of crystallization of calcium sulfate dihydrate at various temperatures and at ionic strengths up to 0.6M. Under all conditions, the rate of reaction is proportional to the square of the relative supersaturation and is controlled by a surface process. The same kinetics are applicable for the growth of calcium sulfate hemihydrate at temperatures above 110 C. The organic phosphonates effectively retard scale formation, and diethylenetriaminepenta (methylenephosphonic acid), when present at a concentration as low as 10−7M, completely inhibits the growth of calicum sulfate hemihydrate at 120 C. By assuming that the inhibitor molecules are adsorbed on growth sites on the surface of the crystals, the inhibition can be interpreted in terms of a simple Langmuir adsorption isotherm.

Symmetrization of Bromobis(polyfluorophenyl)thallium(III) compounds with copper powder

1975 ◽  
Vol 28 (9) ◽  
pp. 1931 ◽  
Author(s):  
GB Deacon ◽  
DG Vince
Keyword(s):  
Diethyl Ether ◽  
Copper Powder ◽  
Grignard Reagents ◽  
Boiling Toluene

Reaction of bromobis(polyfluorophenyl)thallium(III) compounds, R2TlBr (R = C6F5, p-HC6F4, m-HC6F4 or 3,5-H2C6F3) and (C6F5)2TlOH, with copper powder in boiling 1,4-dioxan (diox) or diethyl ether gave the corresponding tris(polyfluorophenyl)thallium(III) compounds, which were isolated as the complexes R3Tl,diox. By contrast, the derivatives R2TlBr (R = o- HC6F4, 3,6-H2C6F3 or Ph) failed to react, and (C6F5)2TlBr was decomposed by copper powder in boiling toluene yielding decafluorobiphenyl. Formation of tris(polyfluorophenyl)thallium(III) compounds is considered to occur via polyfluorophenylcopper(I) intermediates. Treatment of (C6F5)2TlBr with pentafluorophenylcopper in dioxan gave (C6F5)3Tl,diox. The new bromobis-(polyfluorophenyl)thallium(III) compounds, R2TIBr (R = p-HC6F4, m-HC6F4, o-HC6F4, 3,5-H2C6F3 or 3,6- H2C6F3), were prepared by reaction of thallic chloride with the appropriate Grignard reagents.

scholarly journals Flavin-photosensitized reactions of retinal and stilbene

1970 ◽  
Vol 120 (4) ◽  
pp. 673-681 ◽  
Author(s):  
Ann Gordon-Walker ◽  
G. K. Radda
Keyword(s):  
Triplet State ◽  
Diethyl Ether ◽  
Potassium Iodide ◽  
Substrate Concentration ◽  
Transition Energies ◽  
Photostationary State ◽  
Rate Of Reaction ◽  
Paramagnetic Ions

1. Retinol and stilbene are both isomerized when they are illuminated anaerobically in the presence of flavins. 2. Triplet quenchers (e.g. oxygen, potassium iodide and paramagnetic ions) inhibit the reaction more efficiently than they quench flavin fluorescence. At 77°C in a diethyl ether–isopentane–ethanol (5:5:2) glass retinol quenches flavin phosphorescence, but not its fluorescence. 3. For the stilbene reaction cis/trans photostationary-state mixtures are obtained with different flavins and these are linearly related to the phosphorescence transition energies of the flavins used. 4. The reaction involves the triplet state of flavin and a scheme for the reaction is suggested. 5. The dependence of the rate of reaction on substrate concentration is explicable in terms of this scheme. 6. The photobleaching of rhodopsin sensitized by flavin is also demonstrated.

Mechanism of formation of Grignard reagents. Corrosion of metallic magnesium by alkyl halides in ethers

1980 ◽  
Vol 45 (6) ◽  
pp. 1020-1028 ◽  
Author(s):  
Craig L. Hill ◽  
John B. Vander Sande ◽  
George M. Whitesides
Keyword(s):  
Alkyl Halides ◽  
Grignard Reagents ◽  
Mechanism Of Formation ◽  
Metallic Magnesium
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