Manipulating the dynamics of chiral molecular bearings through subtle structural changes of guest molecules

By introducing fluorine substituents, anisotropic rotational motion was induced in diamondoid guests trapped in cylindrical hosts arranged in a 2D honeycomb crystal. Despite the subtle structural changes, the substituent hindered flipping motions in the host and biased its rotations toward tilted precession. The fluorine substituent facilitated the dielectric response of the crystal, as revealed through dielectric constant measurements, which provided insight into the detailed dynamics of the anisotropic rotations. The up-down flipping motion of the guest within the 2D crystal was constrained by an energy barrier but remained manipulable under an external electric field. Consequently, the angular momentum of the spinning guest, with its C−F pole, was forced to align with the applied electric field.