N‐Doped Nonalternant Molecular Bowl/Saddle Hybrids

Abstract

Abstract Herein, we report the straightforward synthesis and properties of N‐doped molecular bowl/saddle hybrids with nonalternant topologies via successive palladium‐catalyzed annulations. Structural evolutions from twisted, bowl‐shaped to bowl/saddle‐hybridized structures are involved during the core‐expansion process, as confirmed by X‐ray crystallographic analyses. Notably, this resultant bowl/saddle‐hybridized molecular carbon shows unique molecular dynamics, as revealed by 1 H NMR, chiral HPLC analyses and theoretical calculations. These molecules exhibit interesting photophysical properties, including moderate fluorescence quantum yields and narrowband emissions. Steady‐state and transient spectroscopy reveal the different photophysical properties in these molecular bowl and bowl/saddle hybrids. Moreover, the molecular bowl/saddle hybrid exhibits the shape‐adaptive character, and allow for multiple bindings with fullerene guests in a stoichiometry ratio of 1:3, which is seldomly observed in most nonplanar molecular carbons. This study not only presents an efficient strategy to construct a new family of N‐doped nonalternant molecular bowl/saddle hybrids, but also provides insights into molecular design of topological nanocarbons with potential applications of chiral materials and organic electronics.