Rate constant for charge transfer

Viggiano A A, Morris R A and Paulson J F 1994 Effects of f and SFg vibrational energy on the rate constant for charge transfer between and SFg int. J. Mass Spectrom. ion Processes 135 31-7... 

By adding small amounts of H2 to the gas mixture and observing the rate of formation of ArH +, they also estimated the following overall rate constants for charge transfer at thermal ion energies. 

Rate constant for charge transfer between donor and acceptor Effective coupling between donor and acceptor states Matrix element of Hamiltonian between diabatic donor and acceptor states... 

Selected Cross Section and/or Rate Constants for Charge-transfer Reactions of He+ and He at Thermal Energies... 

Solution of these equations eventually gives an expression fornj (0), the concentration of electrons at the surface, in terms of the parameters already defined, together with kCT, the rate constant for charge transfer across the interface (see Fig. 10.21) and two recombination constants, one for the bulk and one for the surface. Recombination of hole-electron pairs is taken into account in the development, as is also the formation of surface states by a surface-dependent anion adsorption at a degree of coverage, 9. 

The frequency of the minimum in the semicircle is equal to the sum of the rate constants for charge transfer and recombination o min = ktr + krec. Since it is possible to measure ktr at high band bending where krec is zero, the rate constants can be separated if it is assumed that ktr is independent of potential. 

Table 1 Rate constants for charge transfer between G-C base-pairs (fcht) ...

Fajardo A. M. and Lewis N. S. (1996), Rate constants for charge transfer across semiconductor-liquid interfaces , Science 274, 969-972. 

Kt cms heterogeneous rate constant for charge transfer at an electrode... 

Schlichthorl et al. [177] have used light modulated microwave reflectivity to derive the rates of interfacial electron transfer processes at the n-Si/electrolyte interface. In these measurements, the modulation frequency was constant, and the rate constants for charge transfer were derived from the potential dependent ARm response. Schlichthorl et al. [73] have extended the technique considerably by introducing frequency response analysis. The technique is therefore analogous to IMPS, although, as shown below, it provides additional information. 

The contrast with the microwave results shown in Fig. 24 is striking. A semicircular microwave response is still observed at — l.OV in the plateau photocurrent region, and since recombination is clearly negligible at this potential, the pseudo first order rate constant for charge transfer can be obtained directly from the frequency of the minimum of the semicircle., which in this case is 23 s . At less negative potentials, where recombination takes place, the minimum frequency is determined by the sum of the charge transfer and recombination rate constants. 

Fig. 8. Energy dependence of the rate constants for charge transfer of Ne" with N2, CO and CO (Lindinger and Smith, 1983).

Bisquert J, Zaban A, Greenshtein M, Mora-Serd I (2004) Determination of rate constants for charge transfer and the distribution of semiconductor and electrolyte electronic energy levels in dye-sensitized solar cells by open-circuit photovoltage decay method. J Am Chem Soc 126 (41) 13550-13559... 

Abstract Rate constants for charge transfer processes in the interstellar medium are calculated using ab-initio molecular calculations. Two important reactions are presented the recombination of Si + and Si + ions with atomic hydrogen and helium which is critical in determining the fractional abundances of silicon ions, and the C+ + S -> C + S+ reaction, fundamental in both carbon and sulphur chemistry. 

This study provides reasonably accurate rate constants for charge transfer processes important to model the interstellar medium. The Si + + H and Si + + He reactions are rather efficient charge transfer processes with rate constants of the order of 10 cm s On the contrary, the C+ + S C + S+ charge transfer and its reverse reaction appear to be less efficient, with a rate constant an order of magnitude lower than the one used in the astrochemical model. It might be wise to test the effect of a lower rate coefficient in the chemistry of carbon and sulphur in the interstellar medium. It is important to outline the importance of the n C(2s 2p ) D+ S+(3s 3p )" S level in the mechanism. This state is determinant for the efficiency of the reaction and has to be considered in order to have an accurate description of the collision system. 

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