Electrochemical polymerization of 9-cyanophenanthrene and characterization of its polymer

A novel conducting polymer poly(9-cyanophenanthrene) (P9CP) was synthesized electrochemically by direct anodic oxidation of 9-cyanophenanthrene (9CP) in boron trifluoride diethyl etherate (BFEE). The oxidation onset potential of 9CP in the medium was measured to be 1.6 V vs. a saturated calomel electrode (SCE). P9CP films obtained from BFEE showed good electrochemical behavior and good thermal stability with electrical conductivity of 0.13 S cm−1 in the doped state. The polymer of P9CP may be an attractive candidate material for organic light-emitting material with blue-green-light-emitting upon irradiation with 365 nm UV light. Moreover, the P9CP films on the ITO electrode showed good electrochromic property from dark green to dark yellow, between the doped and dedoped state. FTIR and the quantum chemistry calculation indicated that the 9CP was grown via the coupling of the monomer mainly at the C3, and C12 positions.