Transition metal complexes with photochromic ligands-photosensitization and photoswitchable properties

The development of transition metal complexes with ligands containing different photochromic families has received increasing attention in recent years. Through rational design of the photochromic moieties as ligands, the photochromic properties could be systematically perturbed and varied by relatively simple coordination to different metal centres. In this article, a number of examples, in particular those ligands containing stilbenes, azo compounds, spirooxazines and diarylethenes, are selected to demonstrate the design, perturbation and photosensitization of photochromic moieties with transition metal-ligand chromophores. The photoswitching properties of the transition metal complex functionality are described.