Redox modulation through hydrogen bonding

The above examples clearly demonstrate the profound effect of specific recognition on the redox potentials and vice versa. Specific recognition via hydrogen bonding can also be used to provide site-isolation of an electroactive center, preventing unwanted interactions between individual electroactive molecules. In a recent set of experiments, the effect of recognition-driven encapsulation 

Redox modulation through rr-stacking and donor atom-ir interactions 

In addition to these effects, other electrostatic interactions will affect the redox behavior of redox-active species. A study on flavodoxins for instance, has shown that anionic residues as far away as 13 A have a measurable influence on the FMN cofactor. A different study considering the influence of metal cations on the redox modulation established that Ca binding to a pyrroloquinolinequinone (PQQ) cofactor made the reduction of the oxidized cofactor 570 mV (13kcal/mol) less negative.  

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