In this paper, we report the synthesis and C70 complexation studies of a new fluorescent 5,5'-bi-p-tert-butylcalixarene capsule with an extended hydrophobic cavity. The synthetic route required development of a series of selective protection and de-protection reactions, such as esterification and ester cleavage, as well as a cross-coupling reaction at the lower rim. The resulting 5,5'-bi-p-tert-butylcalixarene was fully characterised, including by X-ray crystallography. In the solid state, the compound exists in an open-capsule orientation, with a perfectly planar bridging biphenylene unit resulting in high fluorescence with a maximum emission peak at 390 nm. Preliminary fluorescence-based complexation experiments with C70 fullerene did not provide conclusive evidence for formation of inclusion complexes.
- C70 fullerene
- Calixarene capsule
- calixarene-fullerene complexation
- chemical sensors
- host-guest systems