A new type of soluble calixarene-based polyimides was prepared by reaction of bis(3-aminopropyl) dipropyl functionalized tetranitrocalixarenes with hexafluoroisopropylidene diphthalic anhydride. Spin-coating of these polymers and subsequent electric field poling results in films that are highly transparent above 410 nm and exhibit high and thermally stable second harmonic generation coefficients. These properties make these materials very suitable Ear frequency-doubling applications in the UV region (820-410 nm).
Kenis, P. J. A., Noordman, O. F. J., van Hulst, N. F., Engbersen, J. F. J., & Reinhoudt, D. N. (1997). Second-order nonlinear optical active calixarene polyimides suitable for frequency doubling in the UV region. Chemistry of materials, 9(2), 596-601. https://doi.org/10.1021/cm960420g