G. Zotti et al., STRUCTURE OF POLYINDOLES FROM ANODIC COUPLING OF INDOLES - AN ELECTROCHEMICAL APPROACH, Chemistry of materials, 6(10), 1994, pp. 1742-1748
The structure of polyindoles from anodic coupling of indole, 5-carboxy
indole, 5-cyanoindole, and biindoles were investigated by cyclic volta
mmetry (CV), FTIR and UV-vis spectroscopies and in situ conductivity.
The presence of the NH signal in the IR spectrum of the neutral polyme
rs indicates that the polyindoles are coupled at the 2 and 3 positions
. The shape and the pH dependence of the CV response, the potential wi
ndow of conductivity, the disappearance of the NH band upon oxidation
and the pH-dependent electrochromism, analogous with those of polyanil
ine, are due to a regular alternance of 2,2 and 3,3 couplings. Polyind
oles of different chain length are produced from anodic coupling of 2,
2'- and 3,3'biindoles.