REGIOSELECTIVE POLYMERIZATION OF 3-(4-OCTYLPHENYL)THIOPHENE WITH FECL3

We have shown that it is possible to regioselectively polymerize 3-(4- octylphenyl) thiophene with FeCl3. Adding FeCl3 slowly to the monomer leads to a soft and therefore regioselective polymerization. The head- to-tail content was determined by H-1 NMR to be 94 +/- 2%. Thin films of the polymer treated with chloroform vapor have an absorption maximu m at 602 nm (2.06 eV) with clear vibronic fine structure. Free standin g films have a conductivity of 4 S/cm, which is 100 times higher than for earlier prepared poly(3-(4-octylphenyl)thiophene). A mechanism for the regioregular polymerization is also proposed.