Preparation of a soluble and neutral alkyl derivative of poly(3,4-ethylenedioxythiophene) and its optical properties

Soluble and non-doped poly(3,4-ethylenedioxythiophene) with a hexyl substit uent (PEDOTh-C-6 (Ni)), was first synthesized by Ni promoted dehalogenation polycondensation of the corresponding monomer. PEDOTh-C-6 (Ni) exhibited g ood solubility in common organic solvents such as CHCl3 CH2Cl2, and DMF, in contrast to poor solubility of the corresponding polymer synthesized by ox idative polymerization. GPC analysis indicated that PEDOTh-C-6 (Ni) had M-n and M-w of 5400 and 8500 (vs polystyrene standards); H-1 NMR analysis gave an M-n value of 11,000. A cast film of PEDOTh-C-6 (Ni) received electroche mical p-doping at 0.20 V vs Ag+/Ag. Chemical and electrochemical oxidation of PEDOTh-C-6 (Ni) led to appearance of new absorption bands in the near in frared region. (C) 2001 Elsevier Science Ltd. All rights reserved.