Poly(3,4-alkylenedioxypyrrole)s: Highly stable electronically conducting and electrochromic polymers

A series of poly(3,4-alkylenedioxypyrrole)s are reported as a new class of electronically conducting polymers exhibiting especially low oxidation pote ntials 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 st ate, passing through a darker intermediate state (brown), as examined by in situ colorimetry. High spectral contrast ratios have been measured through out the visible region with a maximum Delta%T = 76% at 534 nm for poly[3,4- (2,2-dimethylpropylenedioxy)pyrrole) (PProDOP-(CH3)(2)). PProDOP-(CH3)(2) e xhibits outstanding redox switching stability, being able to undergo 40 000 deep double-potential switches between its doped and neutral states (1 s, Delta%T-max = 76%) while retaining more than 90% of its electroactivity. A high level of stability to overoxidation has also been observed as these ma terials show limited degradation of their electroactivity at potentials 2 V above their half-wave potential. Triflate-doped free-standing films of PED OP and PProDOP, having high electrical conductivities of 83 and 95 S/cm, re spectively, have been obtained by galvanostatic deposition at low temperatu re (-7 degrees C).