Poly(3,4-alkylenedioxypyrrole)s:  Highly Stable Electronically Conducting and Electrochromic Polymers

Abstract

A series of poly (3,4-alkylenedioxypyrrole)s are reported as a new class of electronically conducting polymers exhibiting especially low oxidation potentials from ca. -0.6 to -0.4 V vs Fc/Fc + (equivalent to -0.15 to +0.05 V vs SCE) as desired for ambient stability of the doped and conducting states. These polymers exhibit unique combinations of multicolor electrochromism, switching from a red or orange neutral state to a light blue/gray doped state, passing through a darker intermediate state (brown), as examined by in situ colorimetry. High spectral contrast ratios have been measured throughout the visible region with a maximum ∆%T ) 76% at 534 nm for poly[3,4-(2,2-dimethylpropylenedioxy)pyrrole) (PProDOP-(CH3)2). PProDOP-(CH3)2 exhibits outstanding redox switching stability, being able to undergo 40 000 deep double-potential switches between its doped and neutral states (1 s, ∆%Tmax ) 76%) while retaining more than 90% of its electroactivity. A high level of stability to overoxidation has also been observed as these materials show limited degradation of their electroactivity at potentials 2 V above their half-wave potential. Triflate-doped free-standing films of PEDOP and PProDOP, having high electrical conductivities of 83 and 95 S/cm, respectively, have been obtained by galvanostatic deposition at low temperature (-7 °C).

Electrochromic organic and polymeric materials for display applications

“…91 This multichromism is also seen in the substituted PProDOPs and poly(3,4-(butylenedioxy)pyrrole) (PBuDOP). 91 The ability to perform substitution at the nitrogen in PXDOPs has allowed the creation of higher bandgap polymers while maintaining their low oxidation potentials. …”

“…Upon increasing the ring size of the alkyl bridge, another colored state is introduced at low doping levels. 91 For poly(3,4-(propylenedioxy)pyrrole) (PProDOP), the neutral state is an orange color, passes through a brown color upon intermediate doping, and finally to a light gray/blue color upon full oxidation. 91 This multichromism is also seen in the substituted PProDOPs and poly(3,4-(butylenedioxy)pyrrole) (PBuDOP).…”

“…91 For poly(3,4-(propylenedioxy)pyrrole) (PProDOP), the neutral state is an orange color, passes through a brown color upon intermediate doping, and finally to a light gray/blue color upon full oxidation. 91 This multichromism is also seen in the substituted PProDOPs and poly(3,4-(butylenedioxy)pyrrole) (PBuDOP). 91 The ability to perform substitution at the nitrogen in PXDOPs has allowed the creation of higher bandgap polymers while maintaining their low oxidation potentials.…”

Chemical and Electrochemical Synthesis of Highly Conductive and Processable PolyProDOP-alkyl Derivatives

“…[5][6][7][8] By analogy with 3,4-ethylendioxythiophene (EDOT), 9) an appending dioxyalkylene group across the 3-and 4-positions of the pyrrole leads to the polymer with vastly improved properties compared to the parent. With excellent physical properties of PXDOPs, they envisioned that the polymers could be tailored to be processable by appending a alkyl chain to the alkylene bridge of 3,4-propylenedioxypyrrole (ProDOP).…”

Synthesis and Properties of New Small Band Gap Conjugated Polymers: Methine Bridged Poly(3,4-ethylenedioxypyrrole)

“…Recently, poly(3,4-dioxypyrrole) (PXDOP) has been widely studied since it exhibits unique properties of high conductivity, multicolor electrochromism, and rapid redox switching. [29][30][31][32] Although the oxidation potentials of PXDOPs are very low (<0:05 V versus SCE), they exhibit middle to high band gaps of 2.0-3.4 eV. 30 Besides, methine bridged poly(3,4-dioxypyrrole) have not been synthesized and characterized yet.…”