Thermal Decomposition of Diethylketone Cyclic Triperoxide in Polar Solvents

2014 ◽  
Vol 67 (6) ◽  
pp. 881 ◽  
Author(s):  
Gastón P. Barreto ◽  
Elida E. Alvarez ◽  
Gladys N. Eyler ◽  
Adriana I. Cañizo ◽  
Patricia E. Allegretti
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Atom ◽  
Physicochemical Properties ◽  
Kinetic Parameters ◽  
Rate Constant ◽  
Decomposition Mechanism ◽  
Secondary Alcohols ◽  
Polar Solvents ◽  
Secondary Carbon

The thermolysis of diethylketone cyclic triperoxide (3,3,6,6,9,9-hexaethyl-1,2,4,5,7,8-hexaoxacyclononane, DEKTP) was studied in different polar solvents (ethanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, and acetonitrile). The rate constant values (kd) are higher for reactions performed in secondary alcohols probably because of the possibility to form a cyclic adduct with the participation of the hydrogen atom bonded to the secondary carbon. The kinetic parameters were correlated with the physicochemical properties of the selected solvents. The products of the DEKTP thermal decomposition in different polar solvents support a radical-based decomposition mechanism.

THE THERMAL DECOMPOSITION OF TETRAMETHYLTETRAZENE AND TETRAETHYLTETRAZENE

1963 ◽  
Vol 41 (8) ◽  
pp. 1911-1918 ◽  
Author(s):  
B. G. Gowenlock ◽  
P. Pritchard Jones ◽  
D. R. Snelling
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Flow System ◽  
Decomposition Mechanism ◽  
Arrhenius Parameters ◽  
Limiting Pressure

The thermal decompositions of tetramethyltetrazene (TMT) and tetraethyltetrazene (TET) have been studied using a flow system. It is shown that both the decompositions occur at, or above, the limiting pressure for unimolecularity, and Arrhenius parameters for both decompositions are obtained. The decomposition mechanism is discussed in relation to the Arrhenius parameters and theories of three-fragment decompositions. Preliminary values of some kinetic parameters for some reactions of dialkylamino radicals are presented.

A STUDY OF SOME REACTIONS OF THE CYCLOPENTYL RADICAL

1965 ◽  
Vol 43 (3) ◽  
pp. 570-581 ◽  
Author(s):  
Alvin S. Gordon
Keyword(s):  
Hydrogen Atom ◽  
Kinetic Parameters ◽  
Rate Constant ◽  
Energy Of Activation ◽  
Radical Reactions ◽  
Specific Rate ◽  
Exponential Factor ◽  
Allyl Radical ◽  
Specific Rate Constant ◽  
Activated Complex

The specific rate constant for opening the cyclopentyl radical has been determined to be 1014.5 exp –37 700/RT s−1. The energy of activation indicates that any eclipsed pairs of H atoms in the cyclic radical are not de-eclipsed in the activated complex. No evidence for the resulting five-membered linear radical can be found, only evidence for its breakdown products, allyl radical and ethylene.The disproportionation/combination ratio for methyl and cyclopentyl radicals is about 0.3. The energy of activation for methyl abstracting a hydrogen atom from cyclopentane has been confirmed as about 9.5 kcal/mole.Cyclopentyl radical also loses a hydrogen atom to form cyclopentene. The kinetic parameters are difficult to obtain because of radical–radical reactions which form cyclopentene. An analysis of the results indicates an energy of activation at least equal to that for opening the cyclopentyl ring.Evidence is presented to support the view that the cyclopentyl radical loses a molecule of hydrogen to form the resonance-stablized cyclopentenyl radical with an energy of activation close to that for opening the ring, and a pre-exponential factor about 1/10 of that for the opening of the ring.

Complexes of biologically important ligands. I. Ternary complexes of nickel(II) comprising 1,10-o-phenanthrolineazosulfonamide derivatives and alkyldithiophosphates

2006 ◽  
Vol 60 (2) ◽  
Author(s):  
A. Aly ◽  
I. Awad ◽  
M. Abd El-Mottaleb ◽  
K. Abd El-Aal
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Ternary Complexes ◽  
Decomposition Mechanism ◽  
Thermal Decomposition Mechanism ◽  
The Core

Abstract5-[p-(R-Sulfonyl)phenylazo]-1,10-o-phenanthroline (L) and its octahedral complexes of the type [Ni(R2dtp)2(L)] (where R2dtp = diethyl-or dipropyldithiophosphate) with the core NiN2S4 have been prepared and characterized by spectral, magnetic, and thermogravimetric methods. The thermal decomposition mechanism of the compounds was proposed and the kinetic parameters of decomposition were calculated making use of the Coats—Redfern and Horowitz—Metzger equations.

KINETICS AND MECHANISMS OF THE PYROLYSIS OF DIMETHYL ETHER: I. THE UNINHIBITED REACTION

1963 ◽  
Vol 41 (8) ◽  
pp. 1984-1992 ◽  
Author(s):  
D. J. McKenney ◽  
K. J. Laidler
Keyword(s):  
Experimental Study ◽  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Dimethyl Ether ◽  
Rate Constant ◽  
Hydrogen Sulphide ◽  
Pressure Range ◽  
Significant Contribution ◽  
Surface Effect ◽  
Elementary Processes

An experimental study has been made of the thermal decomposition of dimethyl ether, the temperature range being 500 to 550 °C and the pressure range 100 to 700 mm Hg. A considerable surface effect was noted, and the results were not very reproducible. The reaction was of the three-halves order and the rate constant could be expressed as 2.98 × 1014e−54,900/RT cc1/2 mole−1/2 sec−1. On the basis of the results obtained in the presence of hydrogen sulphide (D. J. McKenney and K. J. Laidler. Can. J. Chem. 41, 2009 (1963)) it is concluded that the initiating step, the dissociation of CH3OCH3 into CH3O and CH3, is in its second-order region. In order for the overall order to be three-halves the main terminating step must be either of the type ββM or βμ. The concentrations of the various radicals, and the rates of the various chain-ending steps, are calculated from known or estimated kinetic parameters for the elementary processes. It is concluded that the predominant chain-ending step is probably CH3 + CH3 + M → C2H6 + N, but that there may be a significant contribution from CH3 + CHO + M → CH3CHO + M and from CH3 + CH2OCH3 + M → C2H5OCH3 + M.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Regeneration Mechanism Studied by Potential-Time Response to Sinusoidal Current-Time Function

1997 ◽  
Vol 62 (10) ◽  
pp. 1511-1526
Author(s):  
María-Luisa Alcaraz ◽  
Ángela Molina
Keyword(s):  
Kinetic Parameters ◽  
Rate Constant ◽  
Theoretical Study ◽  
Time Function ◽  
Time Response ◽  
Current Time ◽  
Regeneration Mechanism ◽  
Sinusoidal Current ◽  
Regeneration Processes

A theoretical study of the potential-time response to sinusoidal current applied to static and dynamic electrodes for regeneration processes is presented. Methods for determination of the regeneration fraction, rate constant of the chemical reaction and heterogeneous kinetic parameters are proposed.

Radiolysis studies on the corrosion inhibitors 1 -hexyn-3-ol, cinnamonitrile, and 1,3-diethyl-2-thiourea

1995 ◽  
Vol 73 (12) ◽  
pp. 2137-2142 ◽  
Author(s):  
A.J. Elliot ◽  
M.P. Chenier ◽  
D.C. Ouellette
Keyword(s):  
Hydrogen Atom ◽  
Hydroxyl Radical ◽  
Temperature Dependence ◽  
Rate Constant ◽  
Rate Constants ◽  
Corrosion Inhibitors ◽  
Hydrated Electron

In this publication we report: (i) the rate constants for reaction of the hydrated electron with 1-hexyn-3-ol ((8.6 ± 0.3) × 108 dm3 mol−1 s−1 at 18 °C), cinnamonitrile ((2.3 ± 0.2) × 1010 dm3 mol−1 s−1 at 20 °C), and 1,3-diethyl-2-thiourea ((3.5 ± 0.3) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile and diethylthiourea, the temperature dependence up to 200 °C and 150 °C, respectively, is also reported; (ii) the rate constants for the reaction of the hydroxyl radical with 1-hexyn-3-ol ((5.5 ± 0.5) × 109 dm3 mol−1 s−1 at 20 °C), cinnamonitrile ((9.2 ± 0.3) × 109 dm3 mol−1 s−1 at 21 °C), and diethylthiourea ((8.0 ± 0.8) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile, the temperature dependence up to 200 °C is also reported; (iii) the rate constant for the hydrogen atom reacting with 1-hexyn-3-ol ((4.3 ± 0.4) × 109 dm3 mol−1 s−1 at 20 °C). Keywords: radiolysis, corrosion inhibitors, rate constants.

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