A Crystalline Supramolecular Rotor Functioned by Dual Ultrasmall Polar Rotators^†

Comprehensive Summary As an extended model of conventional molecular rotors, a conceived construction novel crystalline rotor that simultaneously contains two discrete polar rotators is presented here. The supramolecular self‐assembly 18‐crown‐6 host and rotator‐containing ion‐pair guests affords three‐in‐one cocrystal, (2‐NH 3 ‐ i BuOH)(18‐crown‐6)[ZnBr (H 2 O)], in which the hydroxyl group aqua ligand both function as ultrasmall rotators. On basis variable‐temperature single‐crystal X‐ray diffraction, variable‐temperature/frequency dielectric response, density functional theory calculations, dynamics simulations, it found such dual experience gradually enhanced rotation with increasing temperature, more importantly, could be controlled by reversible polar‐to‐polar structural phase transition, i.e. , from “single‐(polar rotator)” state at low‐temperature to “mixed‐dual‐(polar vicinity unusual “synchronized‐dual‐(polar high‐temperature phase.