Electro-optical properties of aromatic oligoazomethine/permethylated α-cyclodextrin main-chain polyrotaxanes

The effect of oligoazomethines (OA) encapsulation into the cavity of permethylated α-cyclodextrin on the electro-optical properties was investigated. The polyrotaxane (OA-Rot) formation leads to distinct improvements in the solubility and film forming ability, as well as photophysical and morphological properties, compared with OA unthreaded analogues. The 2D and 3D AFM images of the OA-Rot film showed a smoother and uniform surface. In addition, the HOMO/LUMO energy levels, as well as the energy band gap of OA-Rot are slightly lower than OA counterpart. As expected, doping of the rotaxane structures with iodine showed a smaller enhancement of the electrical conductivity.