Poly(3,4-ethylenedioxythiophene /hydroxypropyl-β-cyclodextrin) polyrotaxane: Synthesis and photophysical characteristics

We report here the ability of 3,4-ethylenedioxythiophene (EDOT) to form an inclusion complex (IC) with hydroxypropyl-β-cyclodextrin (HPβCD), and the synthesis of poly(3,4-ethylenedioxythiophene/HPβCD) (PEDOT/HPβCD) polypseudorotaxane by oxidative polymerization of the EDOT-HPβCD IC in water using as a catalyst FeCl 3 , followed by end-capping of PEDOT ends with bulky pyrene (Py). The IC was in-depth characterized by molecular docking computations and spectroscopic analyses, including FT-IR, HH-ROESY, 1 H NMR, and UV–Vis titration in water. The computational chemistry confirmed that EDOT can form IC with HPβCD through hydrophobic interactions, and the HH-ROESY NMR spectra indicated that the EDOT monomer is located inside the cavity of HPβCD. Additionally, Job's plot confirmed the 1:1 EDOT-HPβCD IC formation, with a stability constant of about 539 M −1 . The physico-chemical, thermal stability, and prelucrability of PEDOT/HPβCD polyrotaxane in thin films were investigated and compared to the reference PEDOT. The UV–Vis absorption, fluorescence, and lifetimes in acetonitrile (ACN), together with electrochemical properties were evaluated. The dynamic light scattering (DLS) was also employed to study the water dispersion of the material. The measured hydrodynamic diameter (HD) and zeta potential (ZP-ζ) indicated that PEDOT/HPβCD can form a stable water dispersion with an HD of about 300 nm and ZP-ζ = 22.81 mV, respectively. The cyclic voltammetry curve of PEDOT/HPβCD shows an electroactive response. • Inclusion complex (IC) of 3,4-ethylenedioxythiophene and hydroxypropyl-β-cyclodextrin. • Oxidative polymerization of the EDOT-HPβCD IC in water using FeCl 3. • Synthesis of PEDOT/HPβCD polyrotaxane end-capped with pyrene. • PEDOT/HPβCD polyrotaxane forms a stable water dispersion covered by positive charges.