Polarized light induced chiral molecular alignment of achiral Zn(II) and Cu(II) complexes for depth problem

In this chapter, we have designed new metal complexes having rigid Y-shaped structure with photoisomerization moiety expected to occur Weigert effect to be aligned by polarized UV light. Newly prepared PMMA films from DMF solvent were also employed for enhancing molecular orientation phenomenon induced by several types of UV light irradiation not on the surface but even in the films. By using laboratory light source, linearly or circularly polarized UV light was irradiated to the PMMA films containing the metal complexes. For example, after linearly polarized UV light irradiation, optical anisotropy of Zn(II) complex- PMMA sample was observed. Similarly, after circularly polarized UV light irradiation, new CD bands appeared, which suggested chirality attributed not to achiral molecules but to supramolecular arrangement induced by light. Thus, the Zn(II) complex-PMMA was more sensitive to light. Comparison with Cu(II) complexes and proposed effects of chiral light are also mentioned addtionally.