Metallomesogens Derived from Benzimidazoles and α,β-Diketone

• Main Authors: Pu-Jung Huang, 黃柏榮
• Other Authors: Chung-Kuang Lai
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/25988952258936130970

碩士 === 國立中央大學 === 化學研究所 === 98 === In series I the synthesis, characterization and mesomorphic behavior of a series of benzimidazole derivatives 2 and their complexes 1 (M = Cu, Pd, Ni) are described. These compounds have various alkoxy chains attached, and the mesophase exhibited depended on the numbers of alkoxy chains. The mesomorphic properties were investigated using polarized optical microscopy (POM), differential scanning calorimetry (DSC), powder X-ray diffraction (XRD). The results indicated that all ligands based on benzimidazole were not mesogenic. All copper (II) and palladium (II) complexes showed smectic A (SmA) mesophase. However, nickel (II) comlexes with carbon length of n = 10, 12 showed hexagonal columnar mesophase (Colh). The difference in observed mesomorphic behavior might result from the geometry of central core; Cu(II) and Pd(II) ions prefer the square planar geometry, whereas the nikel(II) ion prefer the tetrahedral geometry. In series II and series III, we succeed to synthesize the α,β-diketone derivatives and their complexes (M = Cu, Ni, VO). The results indicated that ligand 4a with carbon length of n = 6, 8, 10, 12 exhibited columnar mesophase.All Copper(II), nickel(II), oxovanadium(II) complexes also exhibited columnar mesophase. In addition, the mesomorphic properties would increase through coordinating with different metals. In series III, the mesomorphic properties observed by these compounds were found to be strongly dependent on the substituent group. The results indicated the the ploarity would be helpful for mesomorphic properties.