Switching metal complexes via intramolecular electron transfer: connections with solvatochromism

Abstract

Metal complexes that can exist in two different charge distributions often exhibit dramatic color changes when switched between them. The underlying spectral changes are fundamentally related to the switchable behavior. In valence tautomeric (VT) systems, the transition is a stimulated, reversible intramolecular electron transfer between a metal center and a ligand, while in charge-transfer-induced-spin-transition (CTIST), also known as electron-transfer-coupled-spin-transition (ETCST), systems, the electron is transferred between two metal centers. We discuss, herein, the relationships between the switchable behavior of these systems and two related optical phenomena: charge transfer and so..