Encapsulation Effects in Catalysis

It is important to realize that the selectivity of a reaction is a matter of relative reaction rates between competitive pathways. Also the isolation (or trapping) of otherwise instable reaction intermediates by encapsulation and issues such as product inhibition can be explained in terms of reaction rates as this is a matter of changing the relative rate of a sequence of reaction steps. It is of great relevance to understand how the rate equation of a reaction changes when the process takes place inside the capsule. 

The rate-constant is a function of the thermodynamic activation parameters i.e. the Gibbs free energy of activation (AG ) and hence the activation enthalpy (AH ) and the activation entropy (AS ) via the Eyring and Arrhenius equations AG = AH - T AS = -RT(lnk) H- c. (T = temperature, R = gas constant, c = a constant). Two extreme scenarios can be distinguished when reactions take place inside a capsule (a practical situation might be a combination of the two)  

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