Autor: |
Klimov, E. S., Muslin, D. V., Lyapina, N. Sh., Shpakov, A. V., Okhlobystin, O. Yu. |
Zdroj: |
Theoretical and Experimental Chemistry; January 1992, Vol. 28 Issue: 1 p61-64, 4p |
Abstrakt: |
The ESR method was used to study a series of sterically hindered silicon-containing phenoxyls — 2-trialkyl(dialkylalkoxy)silyl-4,6-di-tert-butylphenoxyls. The parameters of the ESR spectra were determined: the constants of splitting of the unpaired electron on meta-protons of the phenoxyl ring, protons of the organosilyl substituents, and magnetic silicon nuclei, as well as the spectroscopic splitting factors. The stability of the silicon-containing phenoxyls relative to one another was determined. The influence of a second Si-containing substituent in the ortho-position and an alkyl substituent in the para-position was followed on the example of 2,6-triphenylsilyl-4-tert-butylphenoxyl and the 2,6-trimethylsilyl-4-ethylphenoxyl radical. The stability of the aroxyls is determined primarily by the steric shielding of the radical site responsible for the dimerization-rearrangement reaction. |
Databáze: |
Supplemental Index |
Externí odkaz: |
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