Synthesis, Photophysical and Supramolecular Properties of a pi-Conjugated Molecular Crown Containing a Pentagonal Unit: A Model Compound for Fullerene C-240

摘要

The total synthesis of carbon onions is a significant challenge in the fields of materials science and organic chemistry. To date, the synthesis of even a fragment of fullerene C(240)and its smallest carbon onion C-60@C(240)remains poorly explored. Herein, we demonstrate a bottom-up strategy to produce a novel pi-extended molecular crown-shaped molecule (MC3) containing curved pentagonal and hexagonal units. This molecular crown represents a curved model compound for fullerene C(240)and is fully characterized by NMR, mass spectrometry, UV-vis absorption, and from its emission spectra. Its supramolecular host-guest interaction with fullerene C(60)is also investigated. MC3 and C-60@MC3 can potentially be employed as seeds or templates for the bottom-up synthesis of fullerene C(240)and the carbon onion C-60@C-240, respectively.