Two-Dimensional Chiral Polyrotaxane Monolayer with Emergent and Steerable Circularly Polarized Luminescence

Abstract

Here, we propose a mechanically interlocked strategy to achieve a 2D chiral polyrotaxane (2D CPR) monolayer with emergent and steerable CPL activity by utilizing β-cyclodextrin as the chiral wheel and a luminescent dynamic covalent organic framework as 2D polymeric axle. Such methodology, integrating host-guest and dynamic covalent chemistry, enabled the direct construction of a delaminated 2D CPR monolayer with extraordinarily large size (up to tens of micrometers) and simultaneously endowed chirality to the extended 2D CPR network to generate CPL activity. Importantly, not only the structure but also the CPL performance of the 2D CPR network can be further regulated by the feeding amount of β-cyclodextrin. This work demonstrated a monolayered 2D CPR with CPL activity for the first time. The insightful structure-property relationship of the induced CPL will be of benefit for a deeper understanding of the excited-state chirality of 2D chiral nanomaterials.

Keywords: Chiral polyrotaxane; Circularly polarized luminescence; Covalent organic framework; Mechanically interlocked molecules; Two-dimensional monolayer.