Anhydrous lanthanide chlorides doped rare-earth polyacetylene

Lanthanide chlorides (LnCl₃) of all fifteen rare- earth elements, except Pm, have been used as new dopants for the chemical doping of rare-earth polyacetylene (PA) films. The doping reaction takes place in a saturated tetrahydrofuran solution of LnCl₃. The doped PA films exhibit an increase of 1–3 orders in conductivity as compared with the undoped one and, moreover, can be used as good substrates for the redoping with FeCl₃ or I₂ to prepare films having high and more stable conductivity. Characterizations using techniques of infrared spectrophotometry, electron spin resonance, differential scanning calorimetry and X-ray diffraction have also been performed for the resuttant PA. It is demonstrated by the physical characterizations that the dopant species are partially coordinated to the PA chains but have no significant influence on the PA structure.