摘要
Nitrogen hyperfine splitting constants (aN values) of seven symmetrically para-disubstituted diphenyl nitroxides (1-Y's) were measured by EPR and used in conjunction with five literature values in our correlation analysis. The correlation of these ON values by single-parameter Eq. 1 and dual-parameter Eq. 2 shows that the application of Eq. 2 does not significantly improve the correlation. But our data can also be interpreted by the proposition that the spin-delocalization effect is not completely nonexistent and that it might have revealed itself through the aN values of two very weakly polar substituents with pronounced spin-stabilizing abilities, i.e., SMe and SiMe3.
Nitrogen hyperfine splitting constants (aN values) of seven symmetrically para-disubstituted diphenyl nitroxides (1-Y's) were measured by EPR and used in conjunction with five literature values in our correlation analysis. The correlation of these ON values by single-parameter Eq. 1 and dual-parameter Eq. 2 shows that the application of Eq. 2 does not significantly improve the correlation. But our data can also be interpreted by the proposition that the spin-delocalization effect is not completely nonexistent and that it might have revealed itself through the aN values of two very weakly polar substituents with pronounced spin-stabilizing abilities, i.e., SMe and SiMe3.
基金
Project supported by the National Natural Science Foundation of China.
