[11p-M112-1~15] 12.2 Characterization and Materials Physics

[11p-M112-1] [INVITED] Mechanical motions of rotaxane crystals

〇Masaki Horie¹ (1.National Tsing Hua Univ.)

Keywords:Molecular machines, rotaxane, photoinduced switching

We report the mechanical switching of rotaxane crystals induced by laser irradiation and temperature control. The expansion/contraction of the crystals are induced by a 445-nm laser on/off. Single crystal X-ray crystallography provides the detailed structural changes of the rotaxane molecule. These changes correspond to a change in the size of the crystals with laser irradiation. A microswitch in an electric circuit is demonstrated using a rotaxane crystal. This switching can be repeated more than 500 times without degradation within 60 s. The dynamic photoresponse of rotaxane crystals with azobenzene and ferrocenyl groups in the axle component is also investigated. Repeated alternating laser irradiation of the crystals at 360 and 445 nm produced bending in opposite directions. The rotaxane crystals have two chromophores, bent rapidly and reversibly on irradiation. Such photoinduced molecular switches have many potential applications in mechanical and optoelectric devices based on the simple integration of the interlocked molecules.