Octupolar chimeric compounds built from quinoline caged acetate moieties: a novel approach for 2-photon uncaging of biomolecules

The present study describes the synthesis and investigation of chimeric structures where 6-quinoline and 8-quinoline caging units are integrated in multipolar systems to yield hybrid molecular structures for two-photon uncaging. These systems were demonstrated to exhibit strikingly enhanced (up to more than 2 orders of magnitude larger for octupolar derivatives) two-photon absorption responses in the NIR region compared to common caging groups. Whereas the quadrupolar compound shows the lowest two-photon uncaging cross-section (delta(u)), octupolar chimeric derivatives display one-order larger delta(u) values than their dipolar analogues. This opens a promising route for the design of efficient octupolar type derivatives for two-photon uncaging of biomolecules.