The kinetics of carbonyl radical ring closures

2014 ◽  
Vol 5 (5) ◽  
pp. 1967-1973 ◽  
Author(s):  
Amber N. Hancock ◽  
Carl H. Schiesser
Keyword(s):  
Kinetic Data ◽  
Substitution Reactions ◽  
Radical Ring ◽  
Kinetics Of ◽  
Carbonyl Radical ◽  
Homolytic Substitution

Kinetic data for intramolecular homolytic substitution reactions of a series of acyl and oxyacyl radicals are reported.

The kinetics of alkyl radical ring closures at selenium: formation of selenane

2014 ◽  
Vol 1 (6) ◽  
pp. 645-651 ◽  
Author(s):  
Amber N. Hancock ◽  
Yvonne Kavanagh ◽  
Carl H. Schiesser
Keyword(s):  
Alkyl Radical ◽  
Computational Techniques ◽  
Substitution Reactions ◽  
Radical Ring ◽  
Kinetics Of ◽  
Homolytic Substitution

Intramolecular homolytic substitution reactions of 5-(alkylseleno)pentyl radicals 4 have been investigated by competition kinetics as well as computational techniques.

Decomposition kinetics of cobalt complexes of phenoxy radicals studied by EPR method

1980 ◽  
Vol 45 (2) ◽  
pp. 464-474 ◽  
Author(s):  
Ladislav Omelka ◽  
Alexander Tkáč
Keyword(s):  
Activation Energy ◽  
Room Temperature ◽  
Effective Activation Energy ◽  
Decomposition Kinetics ◽  
Peroxy Radicals ◽  
Substitution Reactions ◽  
Phenoxy Radicals ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Homolytic Substitution

In bimolecular homolytic substitution reactions type SH2 between coordinated peroxy radicals [Co(III)]RO2 and partially hindered bisphenol 4,4'-thiobis-(3-methyl-6-tert-butylphenol) (an antioxidant with commercial name Santonox R) in non-polar medium at room temperature an equilibrium is established between free and Co(III)-coordinated phenoxy radicals. Increasing temperature shifts the equilibrium in favour of the decomplexed free radicals. The complexation-decomplexation process of phenoxy radicals is practically reversible up to 90°C. Polar coordinating solvents (methanol, H2O, diethyl ether, tetrahydrofurane) displace irreversibly the radicals from the complexes. From their decomposition kinetics at various temperatures activation energy of decomplexation by methanol has been determined (110 ± 8 kJ mol-1). The displaced free partially hindered phenoxy radicals are not sufficiently stable and undergo subsequent radical transformations (dimerization, intramolecular and intermolecular H-transfer) with effective activation energy about 67 kJ mol-1.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (03) ◽  
pp. 100-103 ◽  
Author(s):  
C. Schümichen ◽  
J. Waiden ◽  
G. Hoffmann
Keyword(s):  
Glomerular Filtration ◽  
Renal Clearance ◽  
Plasma Protein ◽  
Kinetic Data ◽  
Adult Rats ◽  
Compound A ◽  
Extravascular Space ◽  
Tubular Cells ◽  
Glomerular Filtrate ◽  
Kinetics Of

SummaryThe kinetic data of two different 99mTc-Sn-pyrophosphate compounds (compound A and B) were evaluated in non-adult rats. Only compound A concentrated in bone. Both compounds dispersed rapidly in the intravascular as well as the extravascular space. The plasma protein bond of both compounds increased with time after injection and impaired both the renal clearance of both compounds and the bone clearance of compound A. The renal clearance of both compounds was somewhat above that of 5 1Cr-EDTA. It is concluded that compound A and B is mainly excreted by glomerular filtration. About one fourth of the glomerular filtrate of compound B is reabsorbed and accumulated by the tubular cells.

Kinetics of catalytic conversion of methanol at higher pressures

1980 ◽  
Vol 45 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour
Keyword(s):  
Low Temperature ◽  
Reaction Kinetics ◽  
Water Vapour ◽  
Kinetic Data ◽  
Catalytic Conversion ◽  
The Given ◽  
Kinetics Of

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.

Evidence for general base catalysis by protic solvents in a kinetic study of alcoholyses and hydrolyses of 1-(phenoxycarbonyl)pyridinium ions under both solvolytic and non-solvolytic conditions

2009 ◽  
Vol 74 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Dennis N. Kevill ◽  
Byoung-Chun Park ◽  
Jin Burm Kyong
Keyword(s):  
Second Order ◽  
Base Catalysis ◽  
Substitution Reactions ◽  
Third Order ◽  
Methoxy Derivative ◽  
First Order ◽  
General Base ◽  
Protic Solvents ◽  
Kinetics Of ◽  
Pyridinium Ions

The kinetics of nucleophilic substitution reactions of 1-(phenoxycarbonyl)pyridinium ions, prepared with the essentially non-nucleophilic/non-basic fluoroborate as the counterion, have been studied using up to 1.60 M methanol in acetonitrile as solvent and under solvolytic conditions in 2,2,2-trifluoroethan-1-ol (TFE) and its mixtures with water. Under the non- solvolytic conditions, the parent and three pyridine-ring-substituted derivatives were studied. Both second-order (first-order in methanol) and third-order (second-order in methanol) kinetic contributions were observed. In the solvolysis studies, since solvent ionizing power values were almost constant over the range of aqueous TFE studied, a Grunwald–Winstein equation treatment of the specific rates of solvolysis for the parent and the 4-methoxy derivative could be carried out in terms of variations in solvent nucleophilicity, and an appreciable sensitivity to changes in solvent nucleophilicity was found.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem
Keyword(s):  
Rate Equation ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Complex Mechanism ◽  
First Order ◽  
Absolute Reaction Rate ◽  
First Time ◽  
Kinetics Of ◽  
Absolute Reaction ◽  
Reaction Rate Equation

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.

Sign in / Sign up

Export Citation Format

Share Document