Understanding active species in catalytic transformations: From molecular catalysis to nanoparticles, leaching, Cocktails of catalysts and dynamic systems

In the present review, we consider the transformations of molecular catalysts, leaching, aggregation and various interconversions of metal complexes, clusters and nanoparticles that occur during catalytic processes. The role of catalyst evolution and the mechanistic picture of Cocktail-type systems are considered from the perspective of the development of a new generation of efficient, selective and re-usable catalysts for synthetic applications. Rational catalyst development and the improvement of catalyst performance cannot be achieved without an understanding of the dynamic nature of catalytic systems. (C) 2017 Elsevier B.V. All rights reserved.