Optical limiting properties of optically active metal-free and metal phthalocyanines substituted with chiral binaphthyl crown ether units

The optical limiting properties of five optically active phthalocynines substituted with chiral binaphthyl crown ether units, (R)- and (S)-BNCE-H₂Pc₁ (R)- and (S)-BNCE-CuPc, (S)-BNCE-PbPc, were investigated in solution at 532 nm with 10 ns pulses. The experimental results indicated that the (S)- and (R)-optical isomer exhibit similar optical limiting behavior and the central metal ions, Cu or Pb in the optically active metal phthalocyanine have not significantly enhanced the optical limiting behavior compared with that of the optically active metal-free phthalocyanine. In addition, the nonlinear absorption of the optically active metal-free and metal phthalocyanines was determined by the standard open aperture Z-scan technique.