ANOMALY IN MAGNETIC-PROPERTIES OF POLY(3-ALKYLTHIOPHENE)S DEPENDING ON ALKYL CHAIN-LENGTH

The influence of the alkyl side-chain length exerted on the magnetic p roperties of poly(3-alkylthiophene)s, i.e. poly(3-dodecylthiophene) (P DDT) and poly(3-hexadecylthiophene) (PHDT), has been studied. The temp erature dependences of the magnetic susceptibility and EPR signal have shown that PDDT displays some antiferromagnetic properties at the Nee l temperature of 237 K. However, these properties were unnoticed for P HDT. The anomaly in the magnetic properties of PDDT and PHDT is discus sed within the scope of differences in the crystalline phase of polyme r derivatives brought about by a different alkyl side-chain length.