Host‐Guest Assemblies of Cyanostilbenes and Cucurbit[8]uril: Luminescence Modulation, Photoreactivity Control and Energy Transfer Studies

Abstract

A series of di-cationic cyanostilbene derivatives possessing peripheral alkyl chains of variable lengths underwent host-guest complexation with CB[8] in aqueous media to produce higher order nano-and micro-structures of various morphologies and exhibited multi-color luminescence. Their complexation behavior was modulated by varying the ionic strength of the medium. The photoreactivity of the cyanostilbene chromophores in the CB[8] assemblies was found to be dependent on the length of the alkyl segment. Furthermore, the CB[8] assemblies acted as artificial light harvesting systems exhibiting multicolor luminescence ranging from green to pinkish red through energy transfer to different acceptor dyes.

Fluorescence and Phosphorescence Energy Transfer in Cucurbituril‐Based Supramolecular Systems

“…In the case of Recently, the Banerjee group reported an interesting example of fluorescent supramolecular polymeric assemblies based on the CB [8] and dicationic cyanostilbene derivatives 1 a-f comprising alkyl chains of different lengths (Figure 3). [39] Upon complexation with CB [8], cyanostilbenes with shorter chains 1 a-c (n � 6) mostly formed rectangular microstructures and their original weak cyan fluorescence transformed into the bright greenish-cyan or green one. In the presence of CB [8], the derivatives with longer chains 1 d-f (n � 8), formed nanosized hexagonal assemblies and nanofibers.…”

Cucurbit[8]uril-mediated triphenylamine coumarin derivative cascade assembly for NIR targeted cell imaging

“…1a,10 Supratim Banerjee et al presented a supramolecule assembly of CB [8] with a series of cyanostilbene derivatives to produce multicolor luminescence, and then applied the host-guest system to an artificial light capture system to achieve turquoise, green, yellow, and pink luminescence. 11 George et al utilized CB [7] to encapsulate cationic phthalimide derivatives and further assembled them with LAPONITE s through electrostatic interactions to achieve efficient room-temperature phosphorescence for the photo harvesting energy transfer platform of fluorescent dyes. 12 Liu et al reported a CB [7]-based supramolecular polymer that established cell-cell interactions through hostguest recognition.…”