Photo‐Activated Emission and Chirality Transfer Based on Host–Guest Chemistry of a Motorized All‐Benzene Nanohoop

Abstract

Abstract In this study, a series of motorized carbon nanohoops M[8]CPP , M[9]CPP and M[11]CPP are designed. Transient absorption (TA) spectra reveal these cyclic motors exhibit unprecedented acceleration of rotary speed upon incorporation into an all‐benzene macrocyclic stator, which is attributed to ring strain induced decrease of the steric hindrance at the fjord region. Especially, M[8]CPP realizes 10 7 ‐fold increase of the rotation speed compared with the noncyclic motor. Such high rotation speed leads to the fluorescence quenching of the motorized carbon nanohoops. Interestingly, M[11]CPP possesses a rigid macrocyclic cavity, which can bind with C 60 and C 70 in 1:1 stoichiometric ratio. The formation of host–guest complexes decelerates the photo‐isomerization processes of M[11]CPP and achieves photo‐activated fluorescence emission of the host–guest systems. Furthermore, taking advantage of the intrinsic chirality of M[11]CPP , as well as the CH– π interactions between M[11]CPP and perylene, the chirality is transferred onto perylene, and circularly polarized luminescence is realized. This work not only provides a novel strategy for tuning the optical properties of cycloparaphenylenes through host–guest interactions but also demonstrates the potential of integrating molecular motors into macrocyclic systems to achieve dynamic control over molecular behavior.