Barrier to pyramidal inversion in the tert-butyl radical by electron spin resonance

1976 ◽  
Vol 98 (1) ◽  
pp. 228-230 ◽  
Author(s):  
P. J. Krusic ◽  
P. Meakin
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Tert Butyl ◽  
Pyramidal Inversion ◽  
Butyl Radical ◽  
Spin Resonance

Peri interactions in the 1,3,6,8-tetra-tert-butyl- and 1,3,8-tri-tert-butylnaphthalene anions. Electron spin resonance study

1975 ◽  
Vol 79 (16) ◽  
pp. 1740-1746 ◽  
Author(s):  
Ira B. Goldberg ◽  
Harry R. Crowe ◽  
Richard W. Franck
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Electron Spin Resonance Study ◽  
Tert Butyl ◽  
Spin Resonance ◽  
Spin Resonance Study

An electron spin resonance and CIDEP study of the photoreduction of tert-butyl-p-benzoquinones

1978 ◽  
Vol 56 (6) ◽  
pp. 869-877 ◽  
Author(s):  
Terry Foster ◽  
A. John Elliot ◽  
Babatunde B. Adeleke ◽  
Jeffrey K. S. Wan
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Chemical Equilibrium ◽  
Esr Spectroscopy ◽  
Semiquinone Radical ◽  
Phenoxy Radical ◽  
Decay Kinetics ◽  
Tert Butyl ◽  
Semiquinone Radicals ◽  
Spin Resonance

The photoreduction of 2-tert-butyl-p-benzoquinone and 2,5- and 2,6-di-tert-butyl-p-benzoquinone were studied by esr spectroscopy. In the photolysis of 2,6-di-tert-butyl-p-benzoquinone, only one semiquinone radical was observed and its decay kinetics were monitored by esr. The reduction of the triplet 2-tert-butyl-p-benzoqinone leads to the formation of isomeric semiquinone radicals 1 and 2 in the primary photochemical processes, and this is then followed by a chemical equilibrium between the two isomeric radicals. The relative rates of formation of the two radicals cannot be monitored by conventional esr methods but the CIDEP results show that the formation of radical 2 is about five to seven times faster than that of radical 1. A secondary reaction of the phenoxy radical with a product benzohydrofuran 4 leads to the observation of a polarized radical 3 which derives all its polarization from the primary phenoxy radical.

Electron spin resonance study of tert-butyl halides and carbon tetrachloride, neopentane and carbon tetrachloride binary mixtures irradiated at 77 °K

1969 ◽  
Vol 47 (2) ◽  
pp. 273-278 ◽  
Author(s):  
F. C. Thyrion
Keyword(s):  
Electron Spin Resonance ◽  
Carbon Tetrachloride ◽  
Binary Mixtures ◽  
Electron Spin ◽  
High Efficiency ◽  
Broad Band ◽  
Electron Spin Resonance Study ◽  
Tert Butyl ◽  
Spin Resonance ◽  
High Concentrations

Tert-butyl halides and carbon tetrachloride, neopentane and carbon tetrachloride binary mixtures were irradiated at 77 °K and electron spin resonance spectra were recorded at increasing temperatures until the radicals disappeared.Even at high concentrations of tert-butyl halides, the radicals obtained from CCl4 predominate, indicating that CCl4 has a high efficiency for electron capture. Maximum radical yields and the appearance of a narrow line spectrum with rising temperature were observed in (CH3)3C—X – CCl4 mixtures (X = Cl, Br, I) in concentration ranges where only a single phase exists. This spectrum consists of 17 lines which appear to belong to one odd-numbered spectrum (7 lines due to (CH3)2Ċ—X radical) and two even-numbered spectra (4 and 10 lines, the last being due to (CH3)3Ċ radical). The disappearance of the CCl4 broad band and the appearance of these radicals with increasing temperature can be interpreted as due to charge transfer from carbon tetrachloride cation to tert-butyl halide, facilitated by greater freedom of movement in the solid solutions. In contrast, neopentane and carbon tetrachloride mixtures do not display these features.

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