A Double-walled Noncovalent Carbon Nanotube by Columnar Packing of Nanotube Fragments.

Herein, we report the synthesis of double-walled noncovalent carbon nanotubes (CNTs) through host-guest complexation of nanotube fragments and tube-forming crystal engineering. As the smallest fragment of double-walled CNTs, a host-guest complex of perfluorocycloparaphenylene (PFCPP) and carbon nanobelt (CNB) was synthesized by mixing them in solvents. The immediate complexation of the PF[12]CPP⸧(6,6)CNB complex with a remarkably high association constant (K) of 2×10 L/mol was observed.

Synthesis and size-dependent properties of multiple sizes of chlorinated fluorocycloparaphenylenes.

In recent years, fluorinated cycloparaphenylenes (FCPPs) have attracted attention as electron-negative CPPs as well as cyclic fluoroarenes. Herein, we report the synthesis of heterogenously polyhalogenated CPPs, chlorinated FCPPs (Cl-F[]CPPs; = 6, 8, 10, 12, 14), through nickel- and gold-based methods. The size-dependent photophysical behaviors of Cl-F[]CPPs, which are different from those of pristine CPPs, have been uncovered in this study.

Half-substituted fluorocycloparaphenylenes with high symmetry: synthesis, properties and derivatization to densely substituted carbon nanorings.

Fluorinated cycloparaphenylenes (FCPPs) have attracted attention as electron-accepting CPPs as well as strained fluoroarenes. Herein, we report the synthesis and properties of novel FCPPs; F[8]CPP and F[6]CPP. Furthermore, the derivatization of F[8]CPP afforded a new carbon nanoring where sixteen pyrrole rings are densely substituted on the CPP framework.

Noncovalent Modification of Cycloparaphenylene by Catenane Formation Using an Active Metal Template Strategy.

The active metal template (AMT) strategy is a powerful tool for the formation of mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes, allowing the synthesis of a variety of MIMs, including π-conjugated and multicomponent macrocycles. Cycloparaphenylene (CPP) is an emerging molecule characterized by its cyclic π-conjugated structure and unique properties. Therefore, diverse modifications of CPPs are necessary for its wide application.