The theoretical interpretation of the Linear/circularly polarized light-induced molecular orientation of the azo group-containing trans-Achiral Schiff base dinuclear complex composite material

Nobumitsu Sunaga,Taro Konomi,Masahiro Katoh,Takashiro Akitsul,Katsuyuki Kida

doi:10.1051/matecconf/201713007004

Nobumitsu Sunaga, Taro Konomi + Show 3 more

Open Access

https://doi.org/10.1051/matecconf/201713007004

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Abstract

We have investigated linearly polarized UV and circularly polarized UV light-induced molecular orientation, namely increasing optical anisotropy of newly synthesized AZ containing chiral Schiff base Ni (II), Cu (II) and Zn (II) complexes, as organic/inorganic hybrid materials in polymethylmethacrylate (PMMA) cast films. The driving force and reason for polarized UV light-induced molecular orientation of AZ is so-called Weigert effect. The increase of the dichroic was measured with polarized absorption electronic spectra. In addition, we study on newly synthesized composites of AZ containing chiral Schiff base metal complexes with AZ to irradiate with not only linearly but also circularly polarized UV light (Wavelength selective (260, 318(π-π* of AZ) and 380 nm) and continuous wavelength). In addition, we comparison between simulated by TD-DFT and experimental spectra of electronic and CD spectra, and we calculated dipole moments by TD-DFT. Furthermore, we are using the CD spectrum after circularly polarized light UV irradiation, tried to observation change of supramolecular chiral order of the complexes.

Highlights

In our previous study, by using typical Mn12 singlemolecule magnet[1] and AZ in PMMA cast films, we could observe switching of AC susceptibility in association with photoisomerization of AZ at 3 K .2 C1s and O1s peaks of PMMA could be observed in XPS of the hybrid material, while Mn2p1/2,3/2 peaks, those were shown as bulk Mn12, could not be observed at the surface of PMMA
Polarized UV light irradiation resulted in increasing optical anisotropy, which was observed with polarized UV-vis spectra of π-π*,n-π* and d-d bands
The results suggested that differences in optical anisotropy is ascribed to intermolecular interaction with AZ groups due to flexibility of coordination environment of metal centres of the complexes

Summary

Introduction

By using typical Mn12 singlemolecule magnet[1] and AZ in PMMA cast films, we could observe switching of AC susceptibility in association with photoisomerization of AZ at 3 K .2 C1s and O1s peaks of PMMA could be observed in XPS of the hybrid material, while Mn2p1/2,3/2 peaks, those were shown as bulk Mn12, could not be observed at the surface of PMMA. We have investigated polarized electronic spectra of hybrid material of Mn12 and AZ in PMMA cast film after alternate UV and visible light irradiation for 3 min π-π * and n- π * bands suggested increasing of optical anisotropy accompanying with reversible photoisomerizaion of AZ, which may have resulted in previously reported reversible increasing and decreasing of ac magnetic susceptibility. Increasing optical anisotropy could be observed for hybrid materials composed of chiral trans-type Schiff base Co(II), Ni(II), Cu(II), and Zn(II) complexes and AZ in PMMA cast films after alternate irradiation of polarized UV and visible light .4. In order to elucidate intermolecular interactions by chiral recognition between components effects of conformation of ligands, we prepared and measured hybrid materials composed of enantiomers or diasteromers of Schiff base Mn(III) complexes and AZ in PMMA cast films. One of the ad-vantages of organic/inorganic hybrid materials may be facility of designing supramolecular multifunctional materials, for example metal complexes incorporating azo-ligands with large dichromic ratios.[6,7,8]

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