Heterogeneous one-electron reduction of metal-containing biological molecules using molecular hydrogen as the reductant: synthesis and use of a surface-confined viologen redox mediator that equilibrates with hydrogen

Abstract

Study and use of metal-containing biological reagents often involves the need to manipulate the redox level. We report herein the synthesis of a heterogeneous catalyst system that allows the use of H₂ as a reductant for the one-electron reduction of horseheart ferricytochrome c (cyt cₒₓ), sperm whale myoglobin, and stellacyanin from the lacquer of Rhus vernicifera. Application of the principles illustrated by our catalyst in other systems is possible inasmuch as the reducing power of H₂ is sufficiently great that many biological systems are thermodynamically reducible with H₂. An advantage in using H₂ as a source of reducing power is that the oxidation product is H⁺ which is acceptable since most biological systems are studied in buffered media. A heterogeneous catalyst is desirable to facilitate the separation of the catalyst from the product.

Additional details