Gibbs energy diagram

Let us consider a simple isomerization reaction A B in the solvents I and II, whose abilities to solvate A and B are different. This corresponds to the Gibbs energy diagram shown in Fig. 4-1. 

Fig. 4-1. One-dimensional Gibbs energy diagram for an equilibrium reaction A B in the solvents 1 and 11. Ordinate standard molar Gibbs energies of the reactants A and B in solvents 1 and 11 Abscissa not defined. AG°(1) and AG°(11) standard molar Gibbs energies of reaction in solvents 1 and 11, respectively AGj°(A, 1 11) and AGj°(B, 1 11) standard molar Gibbs energies of transfer of the solutes A and B from solvent 1 to solvent 11, respectively [AGj°(A, 1 11) = G°(A in 1) - G°(A in 11), and AG°(B, 1 11) = G°(B in 1) - G°(B in 11)], cf. Eq. (2-12a) in Section 2.3 = transition state.

The reaetion between the ammonium ion, NH , and trimethylamine, (CH3)3N, analogous to Eq. (4-16), has been studied by pulsed ICR mass spectrometry [115]. The Gibbs energy diagram in Fig. 4-2 describes what happens to the reactants on going from... 

Fig. 4-2. One-dimensional Gibbs energy diagram for the acid/base equilibrium reaction between the ammonium ion and trimethylamine in the gas phase (top) and in aqueous solution (bottom) [115].

Fig. 5-1. One-dimensional Gibbs energy diagram for reaction (5-1) in solution. Ordinate relative standard molar Gibbs energies of reactants, activated complex, and products Abscissa not defined, expresses only the sequence of reactants, activated complex, and products as they occur in the chemical reaction. AG° standard molar Gibbs energy of the reaction AG standard molar Gibbs energy of activation for the reaction from the left to the right.

Fig. 5-2. One-dimensional Gibbs energy diagram for a chemical reaction in three different solvents I, II, and III [cf. Fig. 5-1). (a) Reaction with non-solvated (solvent I) and solvated (solvent II) activated complex (preferential solvation of the activated complex) (b) Reaction with non-solvated (solvent I) and solvated (solvent III) reactants (preferential solvation of the reactants).

Fig. 5-3. One-dimensional Gibbs energy diagram for a chemical reaction in two different solvents I and II [cf. Figs. 5-1 and 5-2). AGj and AG, standard molar Gibbs energies of activation in solvents I and II AG jj and AGj jj standard molar Gibbs energies of transfer of the reactants R and the activated complex from solvent I to solvent II, respectively.

Fig. 5-6. Gibbs energy diagram for (a) one-step cycloaddition reactions proceeding via a dipolar activated complex, and (b) two-step cycloaddition reactions proceeding via a zwitterionic intermediate, in both nonpolar (solvent 1) and polar solvents (solvent II) [92]. For the sake of simplicity, no notice is taken of the different solvation of the initial reactants.

Fig. 5-7. Schematic Gibbs energy diagram for a general aldol addition of enolates to carbonyl compounds in both (a) nonpolar solvents, and (b) polar solvents, according to Heathcock [525].

Figure 1. Gibbs energy diagram electron transfer reaction A + D solution. Adapted from Ref. [3].

See also excited state Gibbs energy diagram. 

See also Gibbs energy diagram Gibbs energy of activation Gibbs free energy stability constant. 

See also potential-energy (reaction) surface Gibbs energy diagram. 

Fig. 7.5 Gibbs energy diagram for the formation of an activated complex in a unimolecular reaction step.

Let us examine the kinetics of the reaction scheme in Figure 6.29 more closely by considering the Gibbs energy diagram in Figure 6.30. If the conformers of 75 are in equilibrium, then... 

Gibbs energy diagram for annealing, reorganization, recrysiallization and deformation... 

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