TY - JOUR
T1 - Solid-State Synthesis of a Conducting Polythiophene via an Unprecedented Heterocyclic Coupling Reaction
AU - Meng, Hong
AU - Perepichka, Dmitrii F.
AU - Bendikov, Michael
AU - Wudl, Fred
AU - Pan, Grant Z.
AU - Yu, Wenjiang
AU - Dong, Wenjian
AU - Brown, Stuart
PY - 2003/12/10
Y1 - 2003/12/10
N2 - Prolonged storage (∼2 years) or gentle heating (50-80 °C) of crystalline 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) affords a highly conducting, bromine-doped poly(3,4-ethylenedioxythiophene) (PEDOT), as confirmed by solid-state NMR, FTIR, CV, and vis-NIR spectroscopies. The novel solid-state polymerization (SSP) does not occur for 2,5-dichloro-3,4-ethylenedioxythiophene (DCEDOT), and requires a much higher temperature (>130 °C) for 2,5-diiodo-3,4-ethylenedioxythiophene (DIEDOT). X-ray structural analysis of the above dihalothiophenes reveals short Hal⋯Hal distances between adjacent molecules in DBEDOT and DIEDOT, but not in DCEDOT. The polymerization may also occur in the melt but is significantly slower and leads to poorly conductive material. Detailed studies of the reaction were performed using ESR, DSC, microscopy, and gravimetric analyses. SSP starts on crystal defect sites; it is exothermic by 14 kcal/mol and requires activation energy of ∼26 kcal/mol (for DBEDOT). The temperature dependence of the conductivity of SSP-PEDOT (σrt = 20-80 S/cm) reveals a slight thermal activation. It can be further increased by a factor of 2 by doping with iodine. Using this approach, thin films of PEDOT with conductivity as high as 20 S/cm were fabricated on insulating flexible plastic surfaces.
AB - Prolonged storage (∼2 years) or gentle heating (50-80 °C) of crystalline 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) affords a highly conducting, bromine-doped poly(3,4-ethylenedioxythiophene) (PEDOT), as confirmed by solid-state NMR, FTIR, CV, and vis-NIR spectroscopies. The novel solid-state polymerization (SSP) does not occur for 2,5-dichloro-3,4-ethylenedioxythiophene (DCEDOT), and requires a much higher temperature (>130 °C) for 2,5-diiodo-3,4-ethylenedioxythiophene (DIEDOT). X-ray structural analysis of the above dihalothiophenes reveals short Hal⋯Hal distances between adjacent molecules in DBEDOT and DIEDOT, but not in DCEDOT. The polymerization may also occur in the melt but is significantly slower and leads to poorly conductive material. Detailed studies of the reaction were performed using ESR, DSC, microscopy, and gravimetric analyses. SSP starts on crystal defect sites; it is exothermic by 14 kcal/mol and requires activation energy of ∼26 kcal/mol (for DBEDOT). The temperature dependence of the conductivity of SSP-PEDOT (σrt = 20-80 S/cm) reveals a slight thermal activation. It can be further increased by a factor of 2 by doping with iodine. Using this approach, thin films of PEDOT with conductivity as high as 20 S/cm were fabricated on insulating flexible plastic surfaces.
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U2 - 10.1021/ja037115y
DO - 10.1021/ja037115y
M3 - Article
C2 - 14653750
AN - SCOPUS:0346124168
VL - 125
SP - 15151
EP - 15162
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 49
ER -