Benchmark Dynamics of Dipolar Molecular Rotors in Fluorinated Metal‐Organic Frameworks

Abstract

Abstract Fluorinated Metal‐Organic Frameworks (MOFs), comprising a wheel‐shaped ligand with geminal rotating fluorine atoms, produced benchmark mobility of correlated dipolar rotors at 2 K, with practically null activation energy ( E a =17 cal mol −1 ). 1 H T 1 NMR revealed multiple relaxation phenomena due to the exchange among correlated dipole‐rotor configurations. Synchrotron radiation X‐ray diffraction at 4 K, Density Functional Theory, Molecular Dynamics and phonon calculations showed the fluid landscape and pointed out a cascade mechanism converting dipole configurations into each other. Gas accessibility, shown by hyperpolarized‐Xe NMR, allowed for chemical stimuli intervention: CO 2 triggered dipole reorientation, reducing their collective dynamics and stimulating a dipole configuration change in the crystal. Dynamic materials under limited thermal noise and high responsiveness enable the fabrication of molecular machines with low energy dissipation and controllable dynamics.