Engineering Switchable Rotors in Molecular Crystals with Open Porosity

The first example of a porous molecular
crystal containing rotors
is presented. The permanently porous crystal architecture is sustained
by rotor-bearing molecular rods which are connected through charge-assisted
hydrogen bonds. The rotors, as fast as 108 Hz at 240 K,
are exposed to the crystalline channels, which absorb CO2 and I2 vapors at low pressure. The rotor dynamics could
be switched off and on by I2 absorption/desorption, showing
remarkable change of material dynamics by the interaction with gaseous
species and suggesting the use of molecular crystals in sensing and
pollutant management.