Photoresponsive self-assembled hexameric capsules based on calix[4]resorcinarenes bearing azobenzene dendron conjugates as side chains

Abstract

We synthesized calix[4]resorcinarenes bearing various azobenzene dendron conjugates as side chains, wherein the azobenzene moiety is a photoresponsive unit and the dendron moiety is a capsule-destabilizing unit, and then studied the photoresponsive properties of their self-assembled hexameric capsules in conjunction with guest encapsulation in H₂O-saturated CDCl₃. It was found that correlation between the trans-to-cis photoisomerization of the azobenzene dendron side chains of hosts and the consequent capsule destabilization leading to guest release largely depends on the nature of the dendron moieties, such as their steric bulkiness or hydrophilicity.