Preparation of plasma-polymerized benzonitrile derivatives and their femtosecond time-resolved optical Kerr effect

Two kinds of linear soluble conjugated polybenzonitrile derivatives, plasma -polymerized aminobenzonitrile (PPABN) and plasma-polymerized nitrobenzonit rile (PPNBN), were successfully prepared by radio frequency glow discharge techniques. The results of Fourier transform infrared (FT-IR) and UV-Visibl e absorption spectra revealed that extensively conjugated C=N double bonds have been formed in the plasma-polymerized benzonitrile derivatives. The fe mtosecond time-resolved optical Kerr effect (OKE) was used to measure the t hird-order optical nonlinearity. For the first time, an ultrafast response and non-resonant OKE of both polybenzonitrile derivatives were observed. Fu rthermore, the effects of molecular weights of polymers and their molecular structures on nonlinear optical properties were also investigated. (C) 200 0 Elsevier Science S.A. All rights reserved.