Electrical and magnetic properties of electro-oxidative polymerized poly(tris(thienylphenyl)amine)s

Electro-oxidative polymerized poly(tris(thienylphenyl)amine)s, which have the hyperbranched (dendritic) structure (PTPA) and linear type (PMeTPA), were investigated for their electrical and magnetic properties. The conductivity PTPA showed was almost one order higher than that of PMeTPA. From the solid state ESR measurements of the polymers, observation of ESR signal at g=2.0027 and 2.0030 indicated the formation of a triphenylamine cation radical. The normalized magnetization plots (M/MS) for PTPA and PMeTPA are close to the theoretical Brillouin curves for S=1, indicating a magnetic interaction between the spin centers in PMeTPA. The spin concentrations determined by the M _s values of PTPA and PMeTPA were 7.3-7.4 and 1.3-1.4%, respectively. This large difference in the spin concentration of the polymers according to the structure resulted from a different spin conformation by the radical structure.