A Multi-Substituted Pyrenyl Carbon Nanohoop: Synthesis, Photophysical and Charge Transport Properties

The longitudinal π-extension of carbon nanohoops is one of the most effective bottom-up synthetic strategies toward carbon nanotubes (CNTs).Herein, the precise synthesis of a multi-substituted carbon nanohoop ([12]CPP-8PBPy) based on cycloparaphenylenes (CPPs) grafted with eight pyrene-functionalized units was reported.This structurally well-defined nanohoop not only acts as a segment of armchair-type CNTs but also achieves enhanced longitudinal π-extension.The structure of [12]CPP-8PBPy was confirmed by high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR).The photophysical properties were studied by UV/Vis and photoluminescence spectroscopy.The potential applications of [12]CPP-8PBPy in electron-transport devices were further investigated.