Abstract
Polyphenylenes insoluble in chlorobenzene were prepared by cationic oxidative polymerization of biphenyl with aluminum trichloride as catalyst and cupric chloride as oxidizer. The fraction insoluble in chlorobenzene was doped in a solution of FeCl3 in acetonitrile. The alternating electrical conductivity, the X-ray diffractograms and the FTIR-spectra of undoped and doped polyphenylenes were measured. The undoped material was observed to be an insulator. Only one sample exhibited different behavior which was similar to the doped material, that was found to be semiconducting. Both undoped and doped polyphenylenes were found to have a monoclinic crystallographic unit cell. For the preparation of polyphenylenes with maximum electrical conductivity after doping, the stoichiometric proportion of biphenyl/CuCl2 = 1/2 has to be chosen. Similarly, the catalyst proportion biphenyl/AlCl3 has to be either 1/0.75 or 1/1.5. Under these conditions the undoped polyphenylenes had a ratio of para/meta substitution of about 1, the degree of crystallinity was below 60% and the unit cell volume was quite low. The results were discussed according to the reactions taken place during polymerization.
Original language | English |
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Pages (from-to) | 181-196 |
Journal | Angewandte Chemie (International Edition) |
Volume | 213 |
Issue number | 1 |
DOIs | |
Publication status | Published - Dec 1993 |