Synthesis and photophysical characteristics of poly(3,4-ethylenedioxythiophene)/β- and γ–cyclodextrins polyrotaxanes

This study reports the synthesis and photophysical characteristics of two polyrotaxanes based on poly(3,4-ethylenedioxythiophene) (PEDOT) encapsulated into βCD or γCD cavities. The synthesis of PEDOT∙βCD and PEDOT∙γCD involve the encapsulation of 3,4-ethylenedioxythiophene (EDOT) as starting monomer inside βCD or γCD cavities, resulting in the formation of EDOT∙βCD and EDOT∙γCD inclusion complexes (ICs). The synthesis of these ICs was proved by molecular docking simulations, UV–Vis titration in water, spectroscopic and thermal approaches, confirming a 1:1 stoichiometry. The oxidative polymerization of ICs in water with FeCl 3 catalyst enabled the synthesis of unstable PEDOT∙βCD and PEDOT∙γCD pseudopolyrotaxanes (PPs). The coupling reaction of PEDOT ends with bulky pyrene (Py) groups converts PPs into polyrotaxanes (PRs) architectures. The chemical structures of PRs were proved by FT-IR and 1 H NMR spectroscopies. Physicochemical characterizations such as the solubility, molecular weights ( M n ), thermal stability, film forming ability, fluorescence (F L ), phosphorescence (pH) quantum efficiencies and lifetimes in solution proved the beneficial impact of the encapsulation process. The HOMO, LUMO and band gap energies, together with the electrical conductivity also confirm that the PRs formation can create a high degree of versatility in the PEDOT'photophysical properties making them promising materials for application in a wide range of organic electronics. • Synthesis of PEDOT∙βCD and γCD polyrotaxanes end-capped with pyrene. • The encapsulation of EDOT into the macrocycles alters the PEDOT packing geometries. • PEDOT∙βCD and PEDOT∙γCD exhibit both fluorescence and phosphorescence. • The electrochemical band gaps of PEDOT∙βCD and PEDOT∙γCD are 2.18 and 1.84 eV.