Application of ion-dipole capture models to inner-sphere reorganization energy of ions in solution

Abstract

suggesting that a major factor in the mechanism of energy transfer involves fast exchange between resonant modes. It should be recalled that the IR spectra of SF6 and n-butane only overlap in the region at 950 ± 30 cm"1 corresponding to triply degenerate fundamental vibrations of both species. Notice that in highly excited n-C4H10+ energy losses would not longer be confined to individual modes due to fast intramolecular relaxation preceding decomposition.25 Inclusion of external rotations to the pool of sharing modes would not substantially modify the above arguments although they may contribute to relax resonance requirements. The fact that toluene is as efficient as SF6 despite having resonant modes at 730, 1500, and 2900 cm"1 reveals that the above conjecture awaits testing in similar experiments involving supersonic (25) M. L. Vestal, J. Chem. Phys., 43, 1356 (1965. beams of selected substrates. Further work is underway.Acknowledgment. Generous support from CIC of Argentina is gratefully acknowledged. Appendix 1Let fx = "1 exp(-x/X) dx be the fraction of molecules which collide between x and (x + dx). Since in this case X(x) = V2'/Z(x), Z(x) = irbx2g«(x), and n(x) = n(0.6)(0.6/x)2, we get X(x) = ax2, with a = 20.1 (x in cm) and for the total fraction of molecules which have collided once after entering the beam before being detected at the ionizer: /= a"1 J exp(-l/ax)x"2 dx = 0.07

Reorganization criteria and their effects on inner-sphere barriers for transition metal redox pairs M(H2O)62+/3+ (M = V, Cr, Mn, Fe and Co)

“…The inner-sphere reorganization energy of these hexahydrate redox pairs were earlier reported, using the semi-empirical quantum chemical INDO method, 13 the classical locked dipole orientation model (LDO) model 14,15 and the improved average dipole orientation (IADO) model. 14,15 In these systems, however, the electron correlation is expected to play an important role. Its neglect would lead to large errors in determining the energies as well as electronic configuration of reacting systems.…”

Hydration Model for the Energy Barrier in Self-Exchange Electron Transfer Reactions in Solution

“…Their summation then gives the total energy contribution. In developing an accurate treatment of the activation and reorganization energies, great progress has been made, − and a considerable amount of theoretical work has been devoted to the development of models.…”

Theoretical studies on the inner‐sphere reorganization energies for the self‐exchange reactions of gas‐phase diatomic molecules HA (A = Mg, Al, Si, P, S, Cl)

“…In Eqs. (18) and (19), f and g are same as those mentioned above and b is the exponential factor of the Morse function [Eq. (7a)l. From those two equations, b is given by…”

“…Those models often work well. In parallel, for the innersphere contribution to RE, after the George-Griffith model was presented on the basis of the harmonic oscillator potential in the 1950s [17], Marcus extended the inner-sphere activation free-energy formula in consideration of the vibrational energy increment caused by the collision interaction among the surrounding medium molecules [2a, lo], and Tunuli and Khan put forward the locked dipole orientation (LDO), the improved average dipole orientation (IADO), and the semiclassical perturbed rotational state (PRS) models [18,19] and the intermediate neglecting differential overlap (INDO/II) MO method 1201 to improve the parameterization of the potential constant factors involved in the George-Griffith formula.…”