The Preparation of Low-Spin trarts-Polyacetylene

: trans-Polyacetylene was prepared directly at 25 °C with a modification of the standard AlEt₃/Ti(0-«-Bu)₄catalyst. The product was characterized by IR, transmission electron microscopy, electron diffraction, photothermal deflection spectroscopy, and electron spin resonance. The product was identical in all respects with trans-polyacetylene prepared by standard routes, except that the number of neutral defects (solitons) is reduced from ~ 1/3000 C atoms to ~ 1/47000 and the line width of the signal due to these defects increased from ~ 1 to 5 G. The reduced defect level makes this an extremely useful material for studying the effect of solitons on the physical properties of polyacetylene.