Polarized spectroscopy and hybrid materials of chiral Schiff base Ni(II), Cu(II), Zn(II) complexes with included or separated azo-groups

Abstract

Chiral Schiff base complexes containing azo-groups, bis(N-R-1-naphtylethyl-4-phenyldiazenylsalicydenaminato) nickel(II), copper(II), and zinc(II) complexes affording a distorted square planar trans-[MN2O2] coordination geometry were prepared newly. Organic/inorganic hybrid materials in polymethylmethacrylate (PMMA) cast films of them (a containing type) or the analogous chiral Schiff base complexes, bis(N-R-1-phenylethyl-3,5-dichlorosalicydenaminato) nickel(II), copper(II), and zinc(II), and azobenzene (AZ) (a separated type) were assembled for comparison of polarized UV light induced molecular arrangement caused by Weigert effect. Investigation of parameters for optical anisotropy of metal complexes as well as AZ suggested that the degree of increasing optical anisotropy of the containing type is higher than that of the separated type based on π–π∗ (of which characteristic band appeared around 380nm), n–π∗, and d–d bands of polarized absorption electronic spectra. Rigid nickel(II) or zinc(II) complexes are easy to increase optical anisotropy than flexible copper(II) complexes for both types.