Oxidation polymerization of N-butyl-N,N-diphenylamine (BDPA) and N-4-butylphenyl-N,N-diphenylamine (BTPA)

N-butyl-N,N-diphenylamine (BDPA) and N-4-butylphenyl-N,N-diphenylamine (BTPA) were polymerized by oxidation polymerization using iron (III) chloride as oxidant. BDPA showed higher polymerizability. Poly(BDPA) and poly(BTPA) showed UV absorption maximum at 362 and 373 nm. Oxidation potential of poly(BDPA) was 1.02 V versus Ag/AgCl, while that of poly(BTPA) was 1.12 V. Hole mobility of poly(BDPA) was 4.93 × 10−5 cm2/Vs and that of poly(BTPA) was 2.89 × 10−5 cm2/Vs at the electric field of 35 V/μm. The differences of the properties were explained by the higher electron donating power of alkyl group than phenyl group and conjugation of phenyl ring. It was found that both poly(BDPA) and poly(BTPA) can be used as hole transporting material for electroluminescent device.