Multivalent and Photoresponsive Assembly of Dual-Cavity Baskets in Water

4 years ago

Multivalent and Photoresponsive Assembly of Dual-Cavity Baskets in Water

Jovica D. Badjić, Shigui Chen, Lu Wang, Taylor Neal

Large unilamellar vesicles [1]n, composed of bolaamphiphilic baskets 1, were found to complex photoresponsive guest 3 and divalent 4 to, respectively, give stable vesicular assemblies [12–3]n and [12–43]n. With the assistance of 1H NMR spectroscopy, electron microscopy, and dynamic light scattering, it was deduced that [12–3]n vesicles comprise ternary [12–3] organized into a curved membrane in which a pair of baskets entraps a laterally positioned dicationic 3. In the case of [12–43]n vesicles, however, the spectroscopic results suggest that three guest molecules 4 insert vertically between four baskets 1 to give pentanary [12–43] packed into the membrane of [12–43]n. Importantly, nanostructured [12–3]n and [12–43]n retain rhodamine B (RhB) in their reservoir (fluorescence microscopy) and can be switched from one into another using UV light, with a disproportionate release of RhB dye. The reported complexes, organized into photoresponsive capsular materials, are rather unprecedented, demonstrating the potential of multivalency for creating functional structures of great interest in the areas of catalysis and delivery. Large unilamellar vesicles comprising dual-cavity basket hosts and photoresponsive guests can now be prepared and used for storing molecular cargo. The switching characteristics and the unique topology of these materials is expected to, in future, provide nanostructured devices akin to those found in the natural world.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201701996