A Geometrically Flexible Three-Dimensional Nanocarbon
Chun Tang, Han Han, Ruihua Zhang, Lygia S. de Moraes, Yue Qi, Guangcheng Wu, Christopher G. Jones, Isabel Hernandez Rodriguez, Yang Jiao, Wenqi Liu, Xuesong Li, Hongliang Chen, Laura Bancroft, Xingang Zhao, Charlotte L. Stern, Qing‐Hui Guo, Matthew D. Krzyaniak, Michael R. Wasielewski, Hosea M. Nelson, Penghao Li, J. Fraser Stoddart
Abstract
The development of architecturally unique molecular nanocarbons by bottom-up organic synthesis is essential for accessing functional organic materials awaiting technological developments in fields such as energy, electronics, and biomedicine. Herein, we describe the design and synthesis of a triptycene-based three-dimensional (3D) nanocarbon, GFN-1, with geometrical flexibility on account of its three peripheral π-panels being capable of interconverting between two curved conformations. An effective through-space electronic communication among the three π-panels of GFN-1 has been observed in its monocationic radical form, which exhibits an extensively delocalized spin density over the entire 3D π-system as revealed by electron paramagnetic resonance and UV–vis–NIR spectroscopies. The flexible 3D molecular architecture of GFN-1, along with its densely packed superstructures in the presence of fullerenes, is revealed by microcrystal electron diffraction and single-crystal X-ray diffraction, which establish the coexistence of both propeller and tweezer conformations in the solid state. GFN-1 exhibits strong binding affinities for fullerenes, leading to host–guest complexes that display rapid photoinduced electron transfer within a picosecond. The outcomes of this research could pave the way for the utilization of shape and electronically complementary nanocarbons in the construction of functional coassemblies.