TRANSPORT AND MAGNETIC STUDIES OF SEGMENTED POLYACETYLENE

Earlier studies of conducting polymers focused on polyacetylene, (CH)x, where extended conjugation lengths and crystallinity are present. We present here the results of a detailed study of temperature dependent magnetic susceptibility and ac and dc transport of [CHDy] and [CHDy÷ZA]x where A is oxygen and iodine and 0.02<_y<0.17. The CHDy introduce sp3 defects along the otherwise sp 2 bonded polyacetylene chains and result in "segmentation " of the chain. Our results show that the presence of the sp3 bonded carbons has only a moderate ffect on the conjugation of the pi band of polyacetylene. EXPERIMENTAL TECHNIQUE Ci_ss-polyacetylene was prepared by the Shirakawa technique [1] at-78°C and isomerized to the trans isomer by heating at ca__~. 150°C for approximately one hour. The trans-(CH)x was n doped to.form (CHYNay+)X using sodium naphthalide solutions o