Synthesis of crystalline molecular gyrotops and phenylene rotation inside the cage.

Phenylene-bridged macrocage molecules were synthesized as molecular gyrotops because the rotor can rotate even in a crystal. The chain-length-dependent properties of the molecular gyrotops were investigated in order to explore the potential to create new molecular materials. The formation of the cage in the synthesis of each molecular gyrotop depended on the length of the alkyl chains of the precursor. The rotation modes and energy barriers for phenylene rotation inside the crystals of the molecular gyrotops were changed by varying the chain length of the cage.