Chiral rhodium(III)-azobenzene complexes as photoswitchable DNA molecular locks.

Chiral rhodium(III)-azobenzene complexes that are able to intercalate into DNA were developed. Upon light exposure, the azobenzene moiety of the metal complexes can photoisomerize from the trans -form to the cis -form, and strongly stabilize the DNA double-helix and modulate DNA transcription. This study presents the first example of metal-based photoswitchable DNA molecular locks.