Non-resonant Nuclear Tunnelling Factor T(298) for Self-exchange in Aqueous Solution [Pg.317]

Non-resonant Golden Rule Nuclear Tunnelling Factor 1 (298) for Self-exchange. [Pg.316]

Electronic non-adiabaticity can give rise to a factor K which is less than unity the nuclear tunnelling factor, T, on the other hand, is always greater than or equal to unity. [Pg.313]

According to a recent model (13) nuclear tunneling factors for the inner-sphere modes can be defined by [Pg.116]

The above treatment neglects nuclear-tunneling effects. The nuclear-tunneling factors calculated for a (hypothetical) electron transfer having the inner-sphere parameters of and [Fe(HjO)jp ions (see Table 1 in 12.2.3.3.4) and no solvent re- [Pg.82]

The high-T limit of Eq. (f) is Eq. (m) of 12.2.3.3.1. At lower T, F 1, and it is necessary to include the nuclear-tunneling factor in this latter equation. When this is done ", results that agree with those given by Eq. (f) are obtained to 20 K. [Pg.70]

Classically, the rate of electron transfer is determined by the rate of passage of the system over the barrier defined by the surfaces. In the semiclassical model (13) a nuclear tunneling factor that measures the increase in rate arising from [Pg.114]

Because typical metal-ligand stretching frequencies are ca. 2 kT at room temperature (T), the possibility that the inner-shell nuclei will tunnel through the potential barrier needs to be considered. This is allowed for through the nuclear-tunneling factor, T j, which is defined by [Pg.66]

To summarize, in this article we have discussed some aspects of a semiclassical electron-transfer model (13) in which quantum-mechanical effects associated with the inner-sphere are allowed for through a nuclear tunneling factor, and electronic factors are incorporated through an electronic transmission coefficient or adiabaticity factor. We focussed on the various time scales that characterize the electron transfer process and we presented one example to indicate how considerations of the time scales can be used in understanding nonequilibrium phenomena. [Pg.127]

The quantity / is just a further combination of constants already in Eq. (10-70). The value of Z is taken to be the collision frequency between reaction partners and is often set at the gas-phase collision frequency, 1011 L mol-1 s-1. This choice is not particularly critical, however, since / is nearly unity unless is very large. Other authors29-30 give expressions for Z in terms of the nuclear tunneling factors and the molecular dimensions. [Pg.244]

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