Theory of Charge Transfer

Assuming thermodynamic equilibrium and Boltzmarm statistics, this rate can be used to determine an average transfer rate at a given temperature T  

In such a case, the rate constant of electron transfer is given by Fermi s golden rule  

2 Theory of Field and Temperature Dependence of Chaise Separation 

The relaxed charge transfer state is assumed to be metastable with a field- and temperature-dependent lifetime r(F, T) = [kcr ssc(F, T) + kcr Gs] The probability for a charge transfer state to dissociate into free charges P(F, T) then 

---

Christov, S. G. Quantum Theory of Charge-Transfer Processes in Condensed Media 28... 

Recent Advances in the Theory of Charge Transfer Kuznetsov, A. M. 20... 

Addition of hydrogen sulfide in solution was found to enhance the rate of this process albeit the efficiencies were generally low, partly due to concomitant precipitation of elemental sulfur during the photolytic experiments. The effects of reaction temperature, light intensity, and pH of the electrolyte were studied, and the photo-catalytic mechanism was discussed with reference to the theory of charge transfer at photoexcited metal sulfide semiconductors. 

In the same year as that of the proposal of the frontier-electron theory, the theory of charge-transfer force was developed by Mulliken with regard to the molecular complex formation between an electron donor and an acceptor 47>. In this connection he proposed the "overlap and orientation principle 48> in which only the overlap interaction between the HO MO of the donor and the LU MO of the acceptor is considered. 

Quite independently, of these fragmentary remarks, a distinctive role of HO (and later LU and SO, too) in unsaturated molecules was pointed out 43> in a general form and with substantiality (cf. Chap. 2). With respect to the molecular complex formation, the theory of charge-transfer force was proposed 47>. A clue tograsp the importance of HO—LU interaction was thus brought to light simultaneously both from the side of ionic reaction and from the side of molecular complex formation. 

Development of the quantum mechanical theory of charge transfer processes in polar media began more than 20 years ago. The theory led to a rather profound understanding of the physical mechanisms of elementary chemical processes in solutions. At present, it is a good tool for semiquantitative and, in some cases, quantitative description of chemical reactions in solids and solutions. Interest in these problems remains strong, and many new results have been obtained in recent years which have led to the development of new areas in the theory. The aim of this paper is to describe the most important results of the fundamental character of the results obtained during approximately the past nine years. For earlier work, we refer the reader to several review articles.1 4... 

The extent to which steric effects adversely affect the attainment of such intimate ion-pair structures would be reflected in an increase in the work term and concomitant diminution of the inner-sphere rate. This qualitative conclusion accords with the reactivity trend in Figure 16. However, Marcus theory does not provide a quantitative basis for evaluating the variation in the work term of such ion pairs. To obtain the latter we now turn to the Mulliken theory of charge transfer in which the energetics of ion-pair formation evolve directly, and provide quantitative informa-... 

---