Electron transfer, activation control irreversible

Conversely, controlled immobilization of enzymes at surfaces to enable high-rate direct electron transfer would eliminate the need for the mediator component and possibly lead to enhanced stability. Novel surface chemistries are required that allow protein immobilization with controlled orientation, such that a majority of active centers are within electrontunneling distance of the surface. Additionally, spreading of enzymes on the surfaces must be minimized to prevent deactivation due to irreversible changes in secondary structure. Finally, structures of controlled nanoporosity must be developed to achieve such surface immobilization at high volumetric enzyme loadings. 

In thermally activated ET we are interested in the electronic states at the transition state (TS). When the system is at equilibrium in either the initial or final state (where D and A are well out of resonance), the diabatic states, xj/j and i/y, can be taken to be essentially the same as their adiabatic counterparts, xj/ and xj/2. When the system with weakly coupled D and A is suddenly carried into the TS by a fluctuation, we adopt the picture that the system remains in the (now nonstationary) xf/ state until (with some finite probability) it dynamically tunnels (see below) to i/y and irreversibly relaxes to the equilibrium product. The required resonance of D and A is a statement of the Franck-Condon control of thermally activated electron transfer [6, 8, 60] that is, at the TS,... 

The irreversible decompositions of permanganates and chromates release a proportion of the anionic constituent oxygen and form a non-volatile metal oxide product. The activation energy for the decomposition of KMn04 is similar to values for the decompositions of the rubidiiun and caesium salts, which suggests a common rate controlling step [32], This is probably electron transfer within the anionic sublattice [11], The Oj released is not extensively adsorbed on the solid products and is not expected to participate further in the anion breakdovm step and, hence, kinetic characteristics are found to be insensitive to reaction conditions and magnitudes of reported by different workers are similar. 

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