Quantum-chemical study of molecular hydrogen binding on [NiFe]-hydrogenase active site

This work is focused on the active site of [NiFe]-hydrogenase. The wide interest in hydrogenases is explained by their potential application in catalytic oxidation and reduction of molecular hydrogen. In this work the H 2 binding to the active site of [NiFe]-hydrogenase is studied using density functional theory methods. The binding energies of H 2 to the iron and nickel centers are found. The intersection between the potential energy curves of the singlet and triplet states of the [NiFe]-hydrogenase active site, with molecular hydrogen bound to it, is demonstrated. The results of this work show that the molecular hydrogen binding to [NiFe]-hydrogenase active site has nonadiabatic spin-forbidden character. Therefore, to create an efficient catalyst based on hydrogenase structural models, it is essential to create bioinorganic complexes capable of changing their spin states during catalytic process.