Synthesis and spin trapping kinetics of new alkyl substituted cyclic nitrones

1982 ◽  
Vol 60 (12) ◽  
pp. 1514-1522 ◽  
Author(s):  
D. L. Haire ◽  
Edward G. Janzen
Keyword(s):  
Comparative Study ◽  
Rate Constants ◽  
Spin Trap ◽  
Spin Trapping ◽  
Absolute Rate ◽  
Cyclic Nitrones ◽  
The Absolute ◽  
Kinetics Of

Three new nitrones, 5-n-propyl-5-methyl-1-pyrroline-N-oxide (PMPO), 5-n-hexyl-5-methyl-1-pyrroline-N-oxide (HMPO), and 5-n-decyl-5-methyl-1-pyrroline-N-oxide (DeMPO), amphiphilic versions of the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), have been synthesized. A comparative study of the absolute rate constants for formation and decay of the tert-butoxyl spin adducts to these cyclic nitrones as well as 3,3,5,5-tetramethyl-1-pyrroline-N-oxide (M4PO) has been undertaken using esr kinetic techniques.

The kinetics of the reactions of atomic hydrogen with halo-ethylenes

1985 ◽  
Vol 63 (8) ◽  
pp. 2127-2130 ◽  
Author(s):  
Mahmooda G. Ahmed ◽  
William E. Jones
Keyword(s):  
Rate Constants ◽  
Atomic Hydrogen ◽  
Pressure Range ◽  
Absolute Rate ◽  
Modest Increase ◽  
The Absolute ◽  
Kinetics Of

The absolute rate constants for the addition of H atoms to C2H3F, 1,1-C2H2F2, C2HF3, C2H3Cl, 1,1 -C2H2Cl2, C2HCl3, and C2H3Br have been determined at 298 ± 2 K over the pressure range 0.70–1.35 Torr. For each of the compounds, the rate constants are found to undergo a modest increase with pressure. At 1.00 Torr the values determined for the rate constants are: C2H3F, (8.86 ± 1.12) × 10−14; 1,1-C2H2F2, (8.16 ± 0.66) × 10−14; C2HF3, (6.21 ± 0.53) × 10−14; C2H3Cl, (27.0 ± 0.5) × 10−14; 1,1-C2H2Cl2, (59.6 ± 3.4) × 10−14; C2HCl3, (10.4 ± 0.8) × 10−14; C2H3Br, (27.8 ± 2.5) × 10−14; in units of cm3 molecule−1 s−1.

The reactions of O(3P) with 2-propanone, 2-butanone, and 3-pentanone

1986 ◽  
Vol 64 (7) ◽  
pp. 1408-1414 ◽  
Author(s):  
John M. Roscoe
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Substrate Concentration ◽  
Activation Energies ◽  
Absolute Rate ◽  
The Absolute

The reactions of O(3P) with 2-propanone, 2-butanone, and 3-pentanone have been studied kinetically as a function of temperature and substrate concentration. The absolute rate constants for these reactions in the gas phase, in the units M−1 s−1, obey the following relations.[Formula: see text]The activation energies for these reactions are comparable to those for the reactions of O(3P) with alcohols, but the preexponential factors for the reactions of O(3P) with these ketones are significantly smaller than those for the analogous reactions with alcohols. The available data indicate that the reactivity of O(3P) toward ketones shows a variation with polar effects of substituents which is similar to that found for the reactions of OH with ketones.

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