Modulation of chiral spectral deflection by van der Waals force-induced molecular electropolarization in catenane oligomers.

The striking chiral optical properties of carbon nanostructures are closely related to the precise three-dimensional spatial arrangement (interaction) of carbon atoms. This work investigated the chiral optical properties of three different structures of all-benzene catenane and trefoil knot regulated by van der Waals (vdW) forces using density functional theory (DFT) calculations and wave function analysis. We systematically illustrate how molecular electrical polarization modulates the chiral optical deflection of alkane oligomers under the induction of van der Waals forces. In this work, the UV-vis spectra, transition density matrices (TDM), and electron-hole density diagrams of three molecules have been studied. Combined with a visualization method to represent the effect of molecular polarization on transition electric/magnetic dipole moments (TEDMs\TMDMs), the results show that vdW interactions can induce chirality deflection in polymers. This mechanism provides a clear direction for designing polymers with specific chirality: by modifying the structure, vdW interactions can be generated in specific regions, and then the chirality of the molecule can be precisely regulated. This will help us to establish a strategy for precisely-oriented design of chiral optical materials, and provide guidance for the application and development of optoelectronic materials in specific fields.