Synergy of Solid-State NMR and Dielectric Spectroscopy Reveals Synchronized Multi-Rotor Dynamics in Crystalline Supramolecular Gyroscopes

Understanding the correlated dynamics of multiple molecular rotators in crystalline supramolecular assemblies is essential for designing functional molecular machines, yet deconvoluting the motions of distinct components remains inherently challenging due to the limitations of individual techniques. Here, we report a synergistic approach that combines solid-state Nuclear Magnetic Resonance (SSNMR) and dielectric spectroscopy to quantitatively resolve multirotor dynamics in a family of isostructural supramolecular gyroscopic complex architectures composed of alkyl ammonium, crown ether, and metal halide hydrate. SSNMR unambiguously reveals both the tert-butylammonium cation and the 18-crown-6 macrocycle as independent rotators─a distinction often ambiguous in such systems. Crucially, by correlating SSNMR-derived dynamics of the crown ether with dielectric relaxation of the coordinated water molecule, we uncover their synchronized rotation across a wide temperature range, mediated by charge-assisted hydrogen bonding. These findings reveal a cooperative multirotor gyroscopic model featuring synchronous rotation of an integrated coaxial crown ether–water–ammonium trio-rotator, accompanied by correlated alkyl reorientation. This synergy validates the dielectric relaxation principle in a complex, multirotor crystalline environment where unambiguous peak assignment has been a longstanding challenge. This work establishes a generalizable methodology for dissecting complex, multicomponent dynamics in crystalline materials, directly bridging molecular-scale motion to macroscopic dielectric response.