Adiabatic, Asymmetric System

ET reactions belong to the few cases when the rate constant k may be calculated on a fundamental level. If the height of the barrier is called AG, k may be written as 

K is the electronic (transmission) factor, equal to the probability to pass the avoided crossing region on the lower PES. We will first assume that k is equal to unity. This is called adiabatic ET and physically means that the system moves exclusively on the lower PES. After the barrier has been passed, the electronic state corresponds to a state where the electron has moved to the other site. 

We will show next how AG may be calculated or measured. Usually, it is possible to determine the free energy AG of the reaction experimentally by measuring the reduction potentials for the acceptor and donor and subtract. If we assume AS = 0, we have ordinary PES based on AH. PES may be assumed to be parabolic. It is also possible to define an effective force constant. 

experimental examples that proved that the inverted region really exists were found (see Miller s experiment in Section 10.5.6). In addition, there was a theory that showed that the Rehm and Weller experiment does not disprove the Marcus inverted region. 

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Hoskin Lambourn (Ref 26) examined the system of a detonation initiated simultaneously at the expl face in contact with one of two metal plates, ie, an asymmetric metal/expl/metal sandwich . They assumed that the detonation products are isentropic with a constant adiabatic exponent = 3, and showed that the motion of both plates can be determined by the continued reflection of centered simple waves. The path of the reflected shock was followed by an approximate method for two traverses of the detonation products, and the process can be continued indefinitely... 

The present volume involves several alterations in the presentation of thermodynamic topics covered in the previous editions. Obviously, it is not a trivial exercise to present in a novel fashion any material that covers a period of more than 160 years. However, as best as I can determine the treatment of irreversible phenomena in Sections 1.13, 1.14, and 1.20 appears not to be widely known. Following much indecision, and with encouragement by the editors, I have dropped the various exercises requiring numerical evaluation of formulae developed in the text. After much thought I have also relegated the Caratheodory formulation of the Second Law of Thermodynamics (and a derivation of the Debye-Hiickel equation) as a separate chapter to the end of the book. This permitted me to concentrate on a simpler exposition that directly links entropy to the reversible transfer of heat. It also provides a neat parallelism with the First Law that directly connects energy to work performance in an adiabatic process. A more careful discussion of the basic mechanism that forces electrochemical phenomena has been provided. I have also added material on the effects of curved interfaces and self assembly, and presented a more systematic formulation of the basics of irreversible processes. A discussion of critical phenomena is now included as a separate chapter. Lastly, the treatment of binary solutions has been expanded to deal with asymmetric properties of such systems. 

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