Potential energy diagrams comparison

Figure 7.19. (Left-hand side) Comparison between experimental sticking coefficients of N2 on Fe(l 11) and the prediction on the basis of Eq. (57) with an activation energy of 0.03 eV. (Right-hand side) Potential energy diagram for molecular nitrogen dissociating on Fe(l 11).

As equilibrium reaction is fast, the energy of activation for this step will have a small value in comparison to other steps. The energy of activation for the second step wil be much larger than the third step since Ki< 2- Hence the required potential energy diagram will have an appearanceas... 

Figure 5 Potential energy diagram of SbBr63 in comparison to the one of InBr63 without the lone pair...

Figure 14. Potential energy diagram for solvation-shell activation of the hydrated proton coupled with quantum-mechanical neutralization and transfer n h at an electrode (a) after Levich et al and (b) comparison with Bell s 2(a) approach and others (Ref. 26b).

The comparison of activation parameters for reactions in different solvents requires consideration of solvation differences of both the reactants and the transition states. The comparison can be done by using potential energy diagrams, such as that illustrated below for two different solvents A and B. It is possible to measure values, which correspond to the enthalpy change associated... 

Given the appropriate potential energy diagrams from the DLVO theory, the stability ratio may be calculated by graphical or numerical integration and then compared with experimental values of W=kyk, the ratio of the experimental rate constants for rapid and slow flocculation. Such a comparison is a severe test of the applicability of theory to experiment, and the observed deviations, although often not appreciable, reflect the assumptions and approximations which are necessary in the calculation of the potential energy terms. An advanced treatment of these issues will be found in Russel et al.- . 

A//jransfer data for n-hcxyl tosylate and several nucleophilic anions are given in Table 4.P1.21. In Table 4.P2.21, the activation parameters for Sjv2 displacement reactions with -hexyl tosylate are given. Use these data to construct a potential energy comparison for each of the nucleophiles. Use these diagrams to interpret the relative reactivity data given in Table 4.P3.21. Discuss the following aspects of the data. 

Fio. 19. Comparison of the two lowest adiabatic ionization potentials in benzene with the three lowest in pyrrole and furan. The values arranged as an energy level diagram were obtained by photoelectron spectroscopy. (T, N. Badwan and D. W. Turner, unpublished work.)... 

A simple diagram depicting the differences between these two complementary theories is shown in Fig. 1, which represents reactions at zero driving force. Thus, the activation energy corresponds to the intrinsic barrier. Marcus theory assumes a harmonic potential for reactants and products and, in its simplest form, assumes that the reactant and product surfaces have the same curvature (Fig. la). In his derivation of the dissociative ET theory, Saveant assumed that the reactants should be described by a Morse potential and that the products should simply be the dissociative part of this potential (Fig. Ib). Some concerns about the latter condition have been raised. " On the other hand, comparison of experimental data pertaining to alkyl halides and peroxides (Section 3) with equations (7) and (8) seems to indicate that the simple model proposed by Saveant for the nuclear factor of the ET rate constant expression satisfactorily describes concerted dissociative reductions in the condensed phase. A similar treatment was used by Wentworth and coworkers to describe dissociative electron attachment to aromatic and alkyl halides in the gas phase. ... 

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