Unprecedented Strong Photoluminescences Induced from Both Aggregation and Polymerization of Novel Nonconjugated β-Cyclodextrin Dimer

Abstract

Although the fascinating emission of natural carbohydrates containing a large number of glucose units has been found and has attracted much interest because of potential applications in biomedical areas, cyclodextrin similar to these carbohydrates has unfortunately not shown analogous luminescent behaviors at room temperature. The objective of this study is to realize the strong fluorescence of cyclodextrin containing no conventional chromophore. In this work, a new diethylenetriamino-styryl-bridged bis (β-cyclodextrin) dimer and its polymer are synthesized by convenient methods, and strong blue photoluminescence is observed even with the naked eye under an ultraviolet lamp. Studies on the molecular structure and the properties of aggregation-induced emission show that the strong fluorescence emissions are produced by the intermolecular hydrogen bonding of amide and hydroxyl groups in aggregation states. Thus, this study opens a new route for synthesizing fluorescent cyclodextrin containing unconventional chromophores for cell imaging, biosensing, and drug delivery.