Quantum Chemical Investigations of Reaction Paths of Metalloenzymes and Biomimetic Models – The Hydrogenase Example

Quantum chemical methods allow one to investigate chemical aspects that are often difficult to evaluate using only experimental approaches. In particular, the continuous increase in reliability and speed of quantum chemical methods has recently allowed the investigation of very complex molecular systems, such as biological macromolecules. In this contribution, we present applications of quantum chemical methods to the investigation of reaction paths of metalloenzymes and related biomimetic models, using hydrogenase models as a reference case. In particular, we discuss several examples from the literature, emphasizing the possibilities (and limitations) offered by present theoretical approaches to study structures, electronic properties and reactivity of metalloenzyme models. Some relevant aspects which have not yet been fully explored using theoretical methods, such as the role of antiferromagnetic coupling and photochemical reactions in [Fe] hydrogenases, are treated in more detail, with presentation and discussion of original data recently obtained in our laboratory.