Monocycle-like Molecular Rotor Induces a Dielectric Relaxation and Dielectric Phase Transformation in an Organic-Inorganic Hybrid Supermolecule

A new strategy for the construction of crystalline supermolecular rotors is presented. We obtained the hybrid crystal [(18‐Crown‐6)K]3[NH2(CH3)2]2(Bi2Cl11)·2DMF (1) by introducing the flexible 18‐crown‐6 into the inorganic [Bi2Cl11]5– binuclear anion cluster lattice through the KCl (screw) to connect the organic molecule with inorganic component, in which the coordinated DMF (N,N‐Dimethylformamide) molecule functions as an polar rotator with monocycle shape, revealed by its significant dielectric relaxation above 358 K. The hybrid solid also exhibits dielectric phase transformation and conductivity switch around 413 K, the response mechanism was investigated by variable‐temperature X‐ray single crystal and powder diffraction as well as DSC, TG techniques. The analysis results reveal that the dielectric anomaly and conductivity switch are triggered by the losing of DMF molecules which is fixed with the [(18‐Crown‐6)K]+. And the ionic conductivity reach to 1.10 × 10–3 S cm–1 at 473 K. The interesting molecular structure and molecular thermal motion feature are promising application in the field of artificial molecular machine and dielectric switch.