Molecular electrochemistry in coordination chemistry: metal-ligand bonds and their activation by electron transfer

Comparing the redox and related properties of series of closed-shell complexes allows the establishment of structure-potential relationships, which are of particular significance to the understanding and prediction of the electron-donor/acceptor properties of ligands and binding metal centers and of the electronic features of their coordination bonds, Conversely, from the knowledge of such properties of these components of coordination compounds, it can be possible, by using empirical or semiempirical expressions, to estimate the redox potentials of their complexes. Moreover, the electroactivation of metal-ligand bonds, particularly in some halide and hydride complexes with rhenium, molybdenum, iron, platinum, or titanium centers, is also discussed in terms of their cathodically or anodically induced weakening towards cleavage, followed by further chemical reactions of the derived unsaturated complexes.