Fluorescent Calixarene Dimers: Synthesis and Optical Properties

Supramolecular chemistry has stimulated the attention of the scientific community over the last few decades. Inspired by nature and exploiting the scope of non-covalent interactions such as hydrogen bonding, electrostatics, and π−π stacking, scientists have developed various synthetic systems with potential for application in different fields (e.g. smart materials, catalysts, optical sensors, complexing agents and nanomedicine).

Several calixarene architectures, a benchmark in supramolecular chemistry, were reported by us as highly sensitive and selective chemosensors. In this communication, the synthesis and structural characterization of a new host calixarene dimer having an enlarged intramolecular cavity specially designed to accommodate large molecular species -such as fullerenes - will be present. Sonogashira cross-coupling was used to assemble the entire unit, which holds a fluorogenic carbazole sub-unit.

The new compound was characterized by FT-IR and ¹H/¹³C and 2D NMR techniques and its photophysical properties studied by UV-Vis and fluorescence spectroscopies. A significant photoluminescence and a great stability toward photobleaching were witnessed for dimer.

Studies concerning the capability of new compound to selectively include C60/C70 compounds and metallophthalocyanines are currently ongoing.