Pyrrolizinofluorene-embedded dithiacalixcorrole(1.0.1.1)s

An unprecedented synthesis of pyrrolizinofluorene moiety embedded dithiacalixcorrole(1.0.1.1)s via [3 + 2] condensation of fluorene-based tripyrrane and appropriate bithiophene diol under TFA-catalyzed conditions is reported. Single crystal X-ray structural analysis revealed that the fluorene unit was inverted and involved in the intramolecular C–N bond formation, resulting in the generation of an unusual pyrrolizinofluorene moiety as part of the dithiacalixcorrole(1.0.1.1) framework. These macrocycles exhibit strong absorption in the UV-visible region and electrochemical studies revealed their electron-rich nature.