A confinement-regulated (H3C–NH3)+ ion as a smallest dual-wheel rotator showing bisected rotation dynamics

Abstract

On the basis of variable-temperature single-crystal X-ray diffraction, rotational energy barrier analysis, variable-temperature/frequency dielectric response, and molecular dynamics simulations, here we report a new crystalline supramolecular rotor (CH₃NH₃)(18-crown-6)[CuCl₃], in which the (H₃C–NH₃)⁺ ion functions as a smallest dual-wheel rotator showing bisected rotation dynamics, while the host 18-crown-6 macrocycle behaves as a stator that is not strictly stationary. This study also provides a helpful insight into the dynamics of ubiquitous –CH₃/–NH₃ groups confined in organic or organic–inorganic hybrid solids.