Controlled Self-Assembly Mediated by the Complexation of Calixpyridinium: Diverse Assembled Morphology, Solid-State Fluorescence, and Iodine Capture Capacity.

It is a great challenge to precisely control the molecules that self-assemble into diverse shapes with diverse properties. Herein, the self-assembled behaviors between calixpyridinium and two pyrenesulfonate guests, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt (PyTS) and sodium 1-pyrenesulfonate (PS), were studied. The morphology and property of the two assemblies were quite different. PS guests self-assembled into spherical aggregates upon complexation with calixpyridinium, while the self-assembled rodlike aggregates were formed via the binding between calixpyridinium and PyTS guests. The calixpyridinium-PS supramolecular aggregates could not emit fluorescence in the solid state, while a strong green fluorescence was emitted by the calixpyridinium-PyTS supramolecular aggregates in the solid state. More interestingly and importantly, the solid calixpyridinium-PyTS supramolecular aggregates exhibited an adsorbent ability to iodine in both the aqueous solution and the vapor phase, while the solid calixpyridinium-PS supramolecular aggregates could not capture iodine. The diverse iodine capture capability of the two supramolecular aggregates was determined by the self-assembled structure at the molecular level.