Perfluorinated aromatic compounds, the so-called perfluoroarenes, are widely used in materials science owing to their high electron affinity and characteristic intermolecular interactions. However, methods to synthesize highly strained perfluoroarenes are limited, which greatly limits their structural diversity. Herein, we report the synthesis and isolation of perfluorocycloparaphenylenes (PFCPPs) as a class of ring-shaped perfluoroarenes. Using macrocyclic nickel complexes, we succeeded in synthesizing PF[n]CPPs (n = 10, 12, 14, 16) in one-pot without noble metals. The molecular structures of PF[n]CPPs (n = 10, 12, 14) were determined by X-ray crystallography to confirm their tubular alignment. Photophysical and electrochemical measurements revealed that PF[n]CPPs (n = 10, 12, 14) exhibited wide HOMO–LUMO gaps, high reduction potentials, and strong phosphorescence at low temperature. PFCPPs are not only useful as electron-accepting organic materials but can also be used for accelerating the creation of topologically unique molecular nanocarbon materials.

The synthesis of each of the cycloiptycene derivatives was achieved in one step from the (6,6)carbon nanobelt.

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Cycloparaphenylenes (CPPs) are ring-shaped aromatic hydrocarbons in which benzene rings are connected to each other at the para-positions. In recent years, fluorinated CPPs (FCPPs) have attracted much attention as electron-accepting CPPs as well as strained fluoroarenes. Herein, we report the synthesis, properties, and derivatization of novel FCPPs; F16[8]CPP (1) and F12[6]CPP (2), in which ortho-difluorophenylene units are circularly connected to form CPP structure. The short-step synthesis of 1 and 2 has been achieved by the strategy using macrocyclic nickel or gold complexes. Furthermore, the derivatization of 1 was successfully achieved to afford a new heteroring-containing carbon nanoring; hexadecapyrrolyl[8]cycloparaphenylene 5, where 16 pyrrole rings are densely substituted on CPP framework.

Peripheral structural modifications of arenes are widely used to control or improve the optoelectronic properties, molecular assembly, and stability of aromatic π-materials as well as to explore new functions. However, known modifications are often tedious and complex; therefore, a simple yet powerful modification strategy is needed. We discovered that annulation with a simple adamantane scaffold exerts a significant impact on the properties, alignment, and stability of aromatic π-systems. This unprecedented adamantane annulation was achieved by a two-step transformation of metallated arenes and 4-protoadamantanone, generating a range of adamantane-annulated arenes. Analysis of structural and electronic properties uncovered unique effects of the process, such as high solubility and enhanced conjugation. The oxidation of adamantane-annulated perylenes produced strikingly stable cationic species with emission extended to the near-infrared region. This simple property modulation of aromatic π-systems would not only create potentially ground-breaking π-materials but also novel nanocarbon materials, such as diamond−graphene hybrids.