H2 and O2 activation by [NiFe]hydrogenases - Insights from model complexes

H-2 is an important compound from both a biological and a chemical industry perspective. Oxidation and reduction enable H-2 to be used as a source of energy and as a raw material in the manufacture of a variety of useful substances. In nature, hydrogenases (H(2)ases) have been entrusted with the task of activating H-2, making it responsible for part of the Earth's energy circulation system since the birth of the planet. H(2)ases have distinctive active centers and their structures and electronic states can be controlled to produce specific functions. This paper provides an overview of the structures and functions of H(2)ases and their models. (C) 2016 Elsevier B.V. All rights reserved.