| Abstract
| - A series of electrochromic N-substituted poly(3,4-propylenedioxypyrrole)s (PProDOPs) arereported, which exhibit the combined properties of a high (>3 eV) electronic band gap, colored oxidativelydoped forms, and easily accessible, low redox potentials. Utilizing methyl (Me), propyl (Pr), octyl (Oct),propanesulfonated (PrS), and ethoxyethoxyethanol (Gly) pendants, the absorbance of the π−π* transitionof the resulting polymers is blue-shifted when compared to the nonderivatized parent. For example, inthe case of poly(N-ethoxyethoxyethanol ProDOP) (N-Gly PProDOP), this transition displays a maximumat 306 nm (onset at 365 nm), providing a colorless and highly transparent neutral polymer with a luminoustransmittance greater than 99% for a film thickness of about 200 nm. N-Substituted PProDOPs displayvery well-defined cyclic voltammograms, with E1/2< −0.1 V vs Fc/Fc+ (+0.2 V vs SCE), negative of theoxidation of water, as desired for materials having stable doped forms and long-lived redox switchingproperties. In addition, the presence of a sulfonate group at the end of the propyl chain in N-PrS PProDOPoffers the possibility of self-doping along with water solubility of the polymer. As a result, N-PrS PProDOPexhibits a fast and regular growth even in the absence of supporting electrolyte. This new family ofpolymers has not only shown interesting electrochromic properties in the visible. Upon doping, a verystrong absorption is observed in the near-infrared (NIR) with changes in transmittance up to 97%,extending the use of these polymers as the active layer in vis−NIR switchable devices.
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