Photoresponsive host-guest chemistry and relaxation time of fluorinated cyclodextrin and arylazopyrazole-functionalized DOTA metal complexes.

Light-responsive modulation of the longitudinal (T1) and transversal (T2*) relaxation times of a fluorinated cyclodextrin has been achieved by host guest complexation with arylazopyrazole-modified metal complexes in aqueous solution. This supramolecular concept can potentially be applied to the development of contrast agents for 19F magnetic resonance imaging (MRI).