Helical self-assembly and nonlinear optical properties of two optically active phthalocyanine derivatives with the same chiral substituents on the α or β position

• Two optically active phthalocyaninato cobalt complexes were synthesized.
• The position of chiral substituents affected the morphology and handedness of the self-assembled aggregates.
• The two complexes showed good third-order nonlinear optical property.

An optically active phthalocyanine derivative with eight (S)-2-methylbutoxy moieties linked on α-position is originally synthesized. Through electronic absorption, circular dichroism (CD), fluorescence spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique, its helical self-assembly and nonlinear optical properties are comparatively investigated with its analogous which has the same chiral moieties linked on β-position substitutions. Although these two complexes possess the same chiral functional group, they exhibit different CD signals in the Q absorption region of corresponding complex and self-assemble into different morphologies. One self-assembles into right-handed ribbon-like aggregates while the other one is left-handed fibers. In addition, both complexes show good third-order nonlinear optical property.

Well-defined aggregates with different morphology, dimension, and handedness were fabricated from phthalocyanine derivatives with same chiral (S)-2-methylbutoxy substituents linked at α or β position, which reveals the position of chiral substituents on the chiral transfer and expression at molecular and supra-molecular level and in turn the morphology, dimension, and handedness of the self-assembled aggregates although both complexes possessing the same chiral functional group.Figure optionsDownload as PowerPoint slide