Activation free energy excited state

The above mentioned deformation in the porphyrin diacid results in decreases in the free energy of activation for thermal atrop-isomerization, AG, of 2-3 kcal/mole compared to the corresponding free bases ( l) Even in the thermal isomerization the greater ground state stability of the trans-2,2 compared to the other isomers is apparent, although not nearly so much so as in the corresponding excited state. 

At each temperature the equilibrium spin glass state is considered to consist of a ground state plus thermally activated droplet excitations of various sizes. A droplet is a low-energy cluster of spins with a volume if and a fractal surface area L. The typical droplet free-energy scales as... 

Fig. 11. Schematic representation of the relationship between the free energy change (difference between the product and reactant minima) and free energy of activation (height of the crossing point with respect to the reactant minimum) for the corss reactions between a single reductant (A ) and a homogeneous series of oxidants (A2a, A2b> A2c) having variable oxidation potential. The curve corresponding to the formation of Ain an excited state is also shown...

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