Table 1. High-temperature polymerization of alkynes and diynes monomer ~~ electric conductivity of polymer film [a] [Sjcm] undoped doped with I, propwe 10-8 l o -' 1-hexyne 10-2 butadiyne 10-8 10 1.5-hexadiyne 10-6 60 [a] Determined with the four-probe technique (4)
The reaction time of the polymerization experiments may be reduced considerably (8 h) by carrying out the above thermal processes in the presence of small amounts of various Lewis acids such as FeCI, or MoCI,.
The undoped polymer films are insoluble in common solvents, possess up to 10% sp3-hybridized carbon atoms as determined by I3C NMR spectroscopy, and are more stable to air than a Shirakawa-polymer film. The oxygen-uptake of the latter amounts to 6 % after 1 hour (in air, room temperature, humidity 50 YO) and reaches 14 YO after 24 hours under the same conditions. A polyene film prepared from propyne by our approach only absorbed 1.5 and 2.7 YO of oxygen after 1 and 24 hours respectively.
The simplicity of this new approach to conducting organic polymers makes it amenable to other highly unsaturated systems (other allenes, cumulenes, alkylacetylenes) and the results of presently performed experiments along these lines will be published in due course.