Premium
Hydrogen‐abstraction reactions from organosilicon compounds. The reactions of methyl, trideuteromethyl, trifluoromethyl, and ethyl radicals with tetramethylsilane
Author(s) -
Kerr J. A.,
Stephens A.,
Young J. C.
Publication year - 1969
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550010306
Subject(s) - chemistry , neopentane , tetramethylsilane , hydrogen atom abstraction , arrhenius equation , organosilicon , radical , medicinal chemistry , activation energy , organic chemistry , molecule
The following Arrhenius parameters have been determined for the hydrogen‐abstraction reactions:R + (CH 3 ) 4 Si → RH + (CH 3 ) 3 SiCH 3TextR Temp. (°K) E (kcal/mole) Log A (mole −1 cc sec −1 ) Log k (400°K) (mole −1 cc sec −1 )CF 3 330–433 7.23 ± 0.09 11.90 ± 0.05 7.95 CH 3 396–476 10.23 ± 0.36 11.55 ± 0.18 5.68 CD 3 396–496 10.36 ± 0.12 11.84 ± 0.06 6.20 C 2 H 5 423–522 11.40 ± 0.48 11.88 ± 0.22 5.68The activation energies are in keeping with the strengths of the bonds formed during the reaction. By comparison with the activation energies for the analogous reactions of neopentane it is estimated that D ((CH 3 ) 3 SiCH 2 H) ≃ 97 kcal/mole. The A factors for the above series of reactions fall within the range predicted by transition‐state theory for this type of process and the validity of previous results of Kerr, Slater, and Young is seriously in doubt.