scholarly journals Hydrogen Abstraction from Dimethyl Sulfide by Trifluoromethyl Radicals

1979 ◽  
Vol 32 (9) ◽  
pp. 2077 ◽  
Author(s):  
NL Arthur ◽  
KS Yeo
Keyword(s):  
Rate Constant ◽  
Additional Data ◽  
Dimethyl Sulfide ◽  
Hydrogen Abstraction ◽  
Reverse Reaction ◽  
Thermochemical Data

Additional data are presented for hydrogen abstraction from (CH3)2,S by CF3 radicals CF3+(CH3)2S → CF3H+CH2SCH2 (1) leading to a revised value for the rate constant (k in cm3 mol-1 s-1, E in J mol-1): logk1 = (11�83�0�06)-(26910�450)/19.16T Combination of these results with thermochemical data gives a revised value of logk-1 = 11�9-61800/19�145Tfor the rate constant of the reverse reaction.

Reactions of trifluoromethyl radicals. I. Hydrogen abstraction from dimethyl sulphide

1972 ◽  
Vol 25 (4) ◽  
pp. 803 ◽  
Author(s):  
NL Arthur ◽  
KS Yeo
Keyword(s):  
Hydrogen Atom ◽  
Rate Constant ◽  
Hydrogen Abstraction ◽  
Reverse Reaction ◽  
Thermochemical Data ◽  
Hydrogen Atom Abstraction ◽  
Dimethyl Sulphide ◽  
Temperature Range

Hydrogen atom abstraction from (CH3)2S by CF3 radicals has been studied in the temperature range 79-167�: (1) CF3 + CH3SCH3 ←→ CF3H + CH3SCH2 (-1) The rate constant, based on Ayscough's value of 1013.36cmS mol-l s-l for the recombination of CF3 radicals, is given by (k1 in cm3 mol-1 s-l, E in J mol-l): Logk1 = (12.05 � 0.02)-(28710 � 130)/2.303RT Combination of these results with thermochemical data gives a calculated value of log k-1 = 12.2 - 62600/2.303RT for the rate constant of the reverse reaction. ΔH�f(CH3SCH2) and S�(CH3SCH2) are estimated to be 155.6 kJ mol-l and 290 J K-l mol-1 respectively.

Reactions of methyl radicals. I. Hydrogen abstraction from dimethyl sulphide

1976 ◽  
Vol 29 (7) ◽  
pp. 1483 ◽  
Author(s):  
NL Arthur ◽  
M Lee
Keyword(s):  
Free Radicals ◽  
Rate Constant ◽  
Rate Constants ◽  
Hydrogen Abstraction ◽  
Reverse Reaction ◽  
Thermochemical Data ◽  
Methyl Radicals ◽  
Dimethyl Sulphide ◽  
Temperature Range

Hydrogen abstraction from (CH3),S and CH3COCH3 by CH3 radicals CH3+CH3SCH3 → CH4+CH3SCH2 CH3 + CH3COCH3 → CH4 + CH3COCH2 has been studied in the temperature range 120-245�. The rate constants, based on the value of 1013.34cm3 mol-l s-1 for the recombination of CH3 radicals, are given by (k in cm3 mol-1 s-1, E in kJ mol-1, R = 0.008314 kJ K-1 mol-1): logk1 = (11.62 � 0.08) ? (38.35 � 0.68)/2.303RT logk3 = (11.61 � 0.05) ? (40.48 � 0.46)/2.303RT Combination of the results for (1) with thermochemical data gives a calculated value of Logk-1 = (11.8 -63.7/2.303RT for the rate constant of the reverse reaction. The results for CH3+(CH3)2S are compared with all of the available data for hydrogen abstraction by free radicals from both sulphur-containing compounds, and molecules of the type (CH3)xM.

Kinetics of radical exchange in the reaction of CF3 radicals with tin tetramethyl

1976 ◽  
Vol 54 (10) ◽  
pp. 1617-1623 ◽  
Author(s):  
T. N. Bell ◽  
P. J. Young
Keyword(s):  
Exchange Reaction ◽  
Rate Constant ◽  
Additional Data ◽  
Hydrogen Abstraction ◽  
Arrhenius Parameters ◽  
Abstraction Reaction ◽  
Reaction Proceeds ◽  
Kinetics Of

The reaction of CF3 radicals with SnMe4 leads to hydrogen abstraction and also radical exchange.[Formula: see text]We propose the exchange reaction proceeds via a five coordinate intermediate. The Arrhenius parameters for the exchange reaction are,[Formula: see text]Additional data for the H abstraction reaction[Formula: see text]combined with previous data yields an improved rate constant for abstraction,[Formula: see text]

Reactions of trifluoromethyl radicals. II. Hydrogen abstraction from monochlorosilane

1973 ◽  
Vol 26 (6) ◽  
pp. 1269 ◽  
Author(s):  
NL Arthur ◽  
BR Harman
Keyword(s):  
Hydrogen Atom ◽  
Rate Constant ◽  
Experimental Error ◽  
Hydrogen Abstraction ◽  
Activation Energies ◽  
Hydrogen Atom Abstraction ◽  
Temperature Range ◽  
Average Value

Hydrogen atom abstraction from SiH3Cl by CF3 radicals ����������������� CF3 + SiH3Cl → CF3H+SiH2Cl������������������� (1) has been studied in the temperature range 69-168�. The rate constant, based on Ayscough's value of 1013.36 cm3 mol-1 s-1 for the recombination of CF3 radicals, is given by (k1 in cm3 mol-1 s-1, E in kJ mol-1): ������������������ logk1 = (12.38�0.06)-(25.72�0.41)/2.303RT At 400 K, the rate constant for CF3 + SiH3Cl is greater than the average value reported for CF3+SiHCl3 by a factor of 3.6. This is due to a difference in A factors since the activation energies are equal within experimental error.

Mass spectrometric study of the reaction of nitrogen atoms with acetaldehyde

1968 ◽  
Vol 302 (1469) ◽  
pp. 167-183 ◽  
Keyword(s):  
Reaction Mechanism ◽  
Mass Spectrometer ◽  
Rate Constant ◽  
Electric Discharge ◽  
Flow System ◽  
Hydrogen Abstraction ◽  
Mass Spectrometric Study ◽  
Mass Spectrometric ◽  
Spectrometric Study ◽  
System A

The reaction of nitrogen atoms, produced by an electric discharge, with acetaldehyde has been studied in a flow system, a mass spectrometer being used to follow the course of the reaction. Sampling was carried out through a small hole in a gold diaphragm. The main stable products were HCN, H 2 and CO; a small amount of glyoxal was also formed. In addition appreciable amounts of a substance yielding ions of m/e = 43 were obtained. Arguments are presented for identifying this with the radical CH 2 CHO. Small amounts of a product giving ions of m/e = 86 were also produced. The nature of this material is discussed. No evidence was obtained for any hydrogen abstraction by nitrogen atoms. Experiments were also carried out with CH 3 CDO to clarify certain aspects of the proposed reaction mechanism . A few experimental results obtained with propionaldehyde can be understood in similar terms. The rate constant of the reaction N + CH 3 CHO → HCN + H 2 + HCO was deduced to be 1.20 ± 0.15 x 10 10 mole -1 cm 3 s -1 at 296°K.

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