Charged cages

Fig. 10. Solute-solvent cage charge-transfer complex model for an electron-transfer reaction between a redox reactant pair donor D and acceptor A...

Heflin, J.R., Marciu, D., Figura, C. et al. (1998) Enhanced nonlinear optical response of an endohedral metallofullerene through metal-to-cage charge transfer. Applied Physics Letters, 72, 2788-2790. 

The reaction mechanism proposed by Koo and Schuster [4], is that of a cage charge annihilation ... 

Fig. 2. Measuring static charge, (a) Field voltage measurement (b) Faraday cage (c) surface resistivity measurement and (d) static decay test.

The internal structure of a liquid at a temperature near its freezing point has been discussed in Sec. 24. Each molecule vibrates in a little cage or cell, whose boundaries are provided by the adjacent molecules, as in Fig. 20, and likewise for each solute particle in solution in a solvent near its freezing point. It is clear that the question of the hydration of ions no longer arises in its original form. In aqueous solution an atomic ion will never be in contact with less than three or four water molecules, which in turn will be in contact with other water molecules, and so on. There is an electrostatic attraction, not only between the ion and the molecular dipoles in immediate contact with it, but also between the ion and molecular dipoles that are not in contact with it. For solvent dipoles that are in contact with a small doubly charged ion, such as Ca++,... 

Although the electrostatic field on the polyelectrolyte surface effectively impedes back ET, it is unable to retard very fast back ET or charge recombination of the primary ion pair within the photochemical cage. The overall quantum yield of photoinduced ET is actually controlled in most cases by the charge recombination. Hence, its retardation is the key problem for attaining high quantum yields in the photoinduced ET. 

Although the electrostatic potential on the surface of the polyelectrolyte effectively prevents the diffusional back electron transfer, it is unable to retard the very fast charge recombination of a geminate ion pair formed in the primary process within the photochemical cage. Compartmentalization of a photoactive chromophore in the microphase structure of the amphiphilic polyelectrolyte provides a separated donor-acceptor system, in which the charge recombination is effectively suppressed. Thus, with a compartmentalized system, it is possible to achieve efficient charge separation. 

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