The optical limiting of blue and green ytterbium double-decker phthalocyanines in solution and in poly(acrylic acid) as thin films

• Neutral bis{tetra(4-tert-butylphenoxy)phthalocyaninato} ytterbium(III) was prepared.
• The complex was reduced resulting in improved nonlinear optical parameters.
• When in thin film the neutral form gave good optical limiting threshold value.

Bis{1(4), 8(11), 15(18), 22(25)-tetra(4-tert-butylphenoxy)phthalocyaninato} ytterbium(III) (2a) (the green form) was synthesized and reduced to form 2b (the blue form). Nonlinear optical parameters for complex 2 in green and blue forms were determined using the Z-scan technique and the values of third-order imaginary susceptibility (Im[χ(3)]) and second-order hyperpolarizability (γ) of the order of 10−9 (for 2b) and 10−27 esu, respectively, were obtained in solution. In poly(acrylic acid) as a thin film, complex 2a showed extremely high Im[χ(3)] and γ values of the order 10−8 and 10−25 respectively. A low optical limiting threshold value of 0.075 J cm−2 was obtained for the thin film 2a.

The blue (reduced) form of bis-{1(4), 8(11), 15(18), 22(25)-tetra(4-tert-butylphenoxy)phthalocyaninato} ytterbium(III) gave improved parameters when compared to the green (neutral) form.Figure optionsDownload as PowerPoint slide