Pillar[5]arene Derivatives Embedded with Aggregation‐Induced Emission Luminogens and Their Fluorescence Regulation.

Through McMurry coupling reaction, three meso‐position functionalized pillar[5]arene derivatives (H‐1, H‐2, and H‐3) have been successfully prepared by embedding aggregation‐induced emission luminogens (AIEgens, diphenyldibenzofulvene (DPDBF) and tetraphenylethylene (TPE)) into the skeleton of supramolecular macrocycles. H‐1, bearing [15]paracyclophane ([15]PCP) and DPDBF moiety, exhibits yellow emission and demonstrates obvious AIE effect. In order to further improve the host‐guest properties of this type of structure, H‐2 and H‐3 are prepared by replacing the [15]PCP moiety with pillar[5]arene backbone, both of which show significant AIE effect and excellent host‐guest complexation properties with pyrazine salt guest G‐1 and 1,4‐dicyanobutane G‐2. Our findings indicate that G‐1 can decrease the fluorescence intensity of the AIE macrocycles, while G‐2 can increase their fluorescence intensity in solution. [ABSTRACT FROM AUTHOR]