Photoswitching the cytotoxic properties of platinum(II) compounds.

The photoactivation of potential anticancer metal complexes is a hot topic of current research as it may lead to the development of more selective drugs. Photoactivated chemotherapy (PACT) with coordination compounds is usually based on a (photo)chemical reaction taking place at the metal center. Herein, a new strategy is exploited that consists of "photomodifying" a ligand coordinated to metal ions. Platinum(II) complexes from photoswitchable 1,2-dithienylethene-containing ligands have been prepared, which exhibit two interconvertible photoisomeric forms that present distinct DNA-interacting properties and cytotoxic behaviors.