Light-driven atropisomeric polymers containing azobenzene moiety as a photorsponsive segment and binaphthyl as an axially chiral segment were designed and synthesized. The polymers were obtained by radical polymerization, and the number-average molecular weight and polydispersity were around 7,000 and 2.0, respectively. The chiral polymer exhibited the glass transition temperature over 75 ^oC with good thermal stability above 280 ^oC. Solution-processed amorphous films could be obtained by spin-coating or drop-casting technique. The films show good uniformity without grain boundary, which are advantageous for fabrication of the thin-film devices. The chiral polymers in the film showed trans-cis photoisomerization upon irradiation at 365 nm for 180 s. The ratio of the trans:cis isomers in the photostationary state was determined to be 60:40. After photo-irradiation of visible light at 436 nm, cis-trans backisomerization occurred clearly. cis-trans thermal backisomerization also took place at 25 ^oC with a half-life of 13 h. Photoisomerization of the chiral polymer gave rise to photo-induced change in optical rotation. Photochemical modulation of the optical rotation reached to 700 ^o, and these values were switched by alternating irradiation between 365 nm and 436 nm. Interestingly, the polymers show fluorescence properties, which is a unique behavior compare to simple azobenzene polymers. Normally, azobenzene compounds are non-fluorescent because of the nonradiative relaxation process of the azo-benzene group caused by the highly efficient trans-cis isomerization. In terms of molecular design, binaphthyl moiety act as fluorescent segment leading to the overall molecule become has fluorescent. Further, a photoswitchable fluorescence behavior was obtained; an increase in the fluorescence intensity after irradiation at 365 nm and recovery to the initial state after irradiation at 436 nm.Additionally, photo-control of molecular orientation of the polymer was explored in the film. After photoirradiation of linearly polarized light at 532 nm, change in refractive index was observed owing to anisotropic molecular orientation. Maximum change in a value of birefringence after irradiation was 6 x 10^-3. These results suggested the chiral polymers are expected to be photoresponsive chiroptical materials for light-driven molecular devices.

The synthesis of a new series of Schiff base ligands is reported. The ligands are fully characterized using ¹H and ¹³C NMR, FT-IR, mass spectrometry and elemental analysis. The extraction and bulk liquid membrane transport abilities of the ligands were evaluated by monitoring the extraction and transport of the metal ions Co(II), Ni(II), Cu(II), Zn(II),Cd(II) and Pb(II) over a 24-hour period. Palmitic acid was included in the organic phase. All ligands showed extraction of Cu(II) and Pb(II) ions, with 2 ligands being more selective towards the extraction of Cu(II) whereas the other 2 ligands extracted more Pb(II). The extraction of Pb(II) is most likely due to a synergistic effect, since palmitic acid was added throughout the organic phase. In the transport studies, only Cu(II) ions were transported. pH-isotherms for both Cu(II) and Pb(II) were also carried out for all ligands. Interestingly Pb(II) is extracted better at lower pH’s  compared to Cu(II) in two cases. This study shows how these salen-type ligands, when used together with palmitic acid, show transport selectivity for Cu(II), and in the extraction studies, extraction selectivity for Cu(II) and  Pb(II). Crystal structures of Ligands L1 and L4 respectively and two Cu(II)-complexes with Ligands L2 and L4 were obtained. The free ligand L1 crystallizes in the C 2/c space group. The final R-factor was 6.2%. The free ligand crystal structure L4 shows a structure similar to that shown with L1 with a final R-factor of 6.1%. The O atoms in this particular structure are in tris conformation to each other. In the crystal structure of the Cu(II) complex with ligand L2, the space group was Pbca and the final R-factor was 8.6%.  The Cu(II) complexes with L4 is a distorted tetrahedral arrangement to the hydroxyl and the azomethine group of an adjacent ligand molecule to form a metallocycle bridged by the linkers. A new crystal structure showing how Pb(II) is coordinated to the Cu(II) complexes of L4 is reported.