Radical stabilization energy table

Table 12.4. Substituent Effects on Radical Stability from Measurements of Bond Dissociation Energies and Theoretical Calculations of Radical Stabilization Energies...

According to these data, which structural features provide stabilization of radial centers Determine the level of agreement between these data and the radical stabilization energies given in Table 12.7 if the standard C—H bond dissociation energy is taken to be 98.8 kcal/mol. (Compare the calculated and observed bond dissociation energies for the benzyl, allyl, and vinyl systems.)... 

Table 1 Radical stabilization energies (in kj/mol) of monosubstituted methyl radicals at 0 K according to Eq. 1... 

Table 6.11 Calculated radical stabilization energies at 0 K for the cyanomethyl radical (kJ/mol).8...

Table 6.13 Comparison of experimental radical stabilization energies at 0 K (k J/mol) of substituted methyl radicals with those calculated with DFT-based electronic structure methods.

Table 7 Radical-stabilization energies (RSE) (kcal mol ) for radicals derived from a-substituted acetophenones, PhCOCHjR."...

TABLE 7.1. Radical Stabilization Energies (kJ/mol) of Mono- and Disubstituted Methyl Radicals,... 

Radical stabilization energies calculated according to Equation 5.3 at 298.15 K have been compiled in Table 5.4 for a variety of monosubstituted methyl radicals at either G3(MP2)-RAD or higher level. In those cases in which results are available at more than one theoretical level, good agreement between these results is usually found. Overall, the mean absolute deviation of the G3(MP2)-RAD values from experiment is... 

Substituent effects on radicals can be expressed as radical stabilization energies (RSE). Table 3.17 gives some RSEs determined by one such approach developed by Leroy, which can be defined as the difference between the observed enthalpy of atomization. H and the sum of standard bond energies. 

Table 11.1. Substituent Effects on the Stability of Allylic and Benzylic Radical from Calculation of Radical Stabilization Energy... 

Table 11.11. Radical Stabilization Energy (SE) as Defined in Figure 11.16... 

TABLE 5.1 Radical Stabilization Energies for Selected Substituents at 0 K... 

The radical stabilization provided by various functional groups results in reduced bond dissociation energies for bonds to the stabilized radical center. Some bond dissociation energy values are given in Table 12.6. As an example of the effect of substituents on bond dissociation energies, it can be seen that the primary C—H bonds in acetonitrile (86 kcal/mol) and acetone (92kcal/mol) are significantly weaker than a primaiy C—H... 

Table 12.7. Thermochemical Stabilization Energies for Some Substituted Radicals...

For comparison purposes activation energies for reaction 12, in both gas and liquid phase, are collected in Table 5. The value for the a-toluenesulfonyl radical is in line with the activation energies of the other RS02 desulfonylations, provided allowance is made for differences in the stabilization energies of the organic radicals that are produced. However, electrostatic repulsions within the radical molecule and phase effect may considerably influence activation energies. 

---