Columnar and Discotic Nematic Superstructures from Monomers and Dimers of Pentaynylbenzene Derivatives.
| Autor: | Ching-Ting Liao, 廖竟婷 |
|---|---|
| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 In the first part of the thesis, compounds are designed from pentaynyl- benzene by attaching various groups of the sixth position of the central benzene ring to realize the effect pentaynylbenzene dimers were obtained utilizing on liquid crystal properties. Moreover, a platinum-containing unit as a linker for manipulation of intermolecular interactions. As a result, wider liquid crystal temperature ranges and lower phase transition temperatures were achieved. The liquid crystal temperature range of platinum containing monomer and dimer are 106 oC and 165 oC respectively. In the second part, one more alkoxy chain was added on each peripheral phenyl rings of pentaphenylynylbenzene. Such modification should lead to strengthened the Van der Waals force and hindered rotation of the peripheral phenyl rings to favor highly ordered columnar phases. Monomeric compounds containing two octyloxy chains on each peripheral phenyl ring show wider liquid crystal temperature ranges than those of other chain lengths. However, due to sterric effect callapases the columnar order of the monomer callapses for the organic and metal-containing dimers to exhibit no liquid crystal properties. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|