CHARGE-TRANSFER COMPLEXES BETWEEN POLYACETYLENE-TYPE POLYMERS AND IODINE IN SOLUTION

In our further investigation on the conjugation of 1,4-polyisoprene by iodine,1 we found charge-transfer complexes from the resultant conjugated segments and iodine in solution. In particular, when the conjugation reaction is carried out in a two-phase solution, where a polyisoprene-containing CCl4 phase equilibrates immiscibly with an I2-saturated methanol solution, formation of the charge-transfer complexes can be readily detected by optical spectroscopy. The charge-transfer complex formation is shown to be accompanied by a transformation of the outer change-transfer complexes to inner complexes, producing I3-, a sort of ion which also exists in I2-doped polyacetylene films.2