| Abstract: | 本篇論文以合成三系列具不同結構形式之配位基及其金屬錯合物，與分別探考其可能之液晶相行為及性質。此三系列分為：系列一dicopper (II) complexes of 3, 4, 5-trialkoxybenzoicacid-(2-hydroxy-4- alkoxybenzyidine)hydrazides，系列二dicopper (II) complexes of 4-(tetra decanoxy-benzoicacid4-[(3,4-dialkoxybenzoyl)hydrazonomethy]-3- hydroxyphenyl esters，以及系列三2, 6-bis-(3, 4, 5-trialkoxyphenyl)- benzo[1, 2-d; 5, 4-d’]bisoxazoles。 於分子結構設計中，我們藉著改變兩邊側鏈柔軟支鏈之碳鏈長度、支鏈數目與配位基中段連接基種類，來探討其對液晶相形成所產生之影響。實驗藉1H及13C-NMR光譜來鑑定合成化合物之結構，並由元素分析值以確定錯合物之純度。於液晶相行為之探討部分，我們藉偏光顯微鏡下對不同相溫度變化範圍及液晶相種類作一初步觀察，再以DSC熱分析儀對相變化溫度及熱含量變化判別。 實驗結果得知，系列一之dicopper (II) complexes of 3,4,5-tri alkoxybenzoicacid -(2-hydroxy-4-alkoxybenzyidine)hydrazides，當其側鏈基數目為六或八根時，此系列之化合物皆為盤狀液晶，液晶相結構為Colh phase。於系列二dicopper (II) complexes of 4-(tetradecanoxy- benzoicacid4-[(3,4-dialkoxybenzoyl)-hydrazonomethy]-3-hydroxyphenyl esters；當化合物中間連接基為醚化基時，側邊只需六根側鏈基便具液晶相，然而，中間連接基為酯化基時，側邊則需增加至十根側鏈基才具液晶相，其二者之液晶相結構皆為Colh phase。系列三2, 6-bis(3, 4, 5-trialkoxphenyl)benzo[1, 2-d; 5, 4-d’]bisoxazoles，側鏈基之alkoxy groups碳數為n = 8、10、12或14時，皆具有Colh之液晶相。 This thesis describes the synthesis, characterization and meso- morphic properties of three series (Series I , II , III) of organic ligands and their copper(II) complexes. These compounds include; Series I dicopper (II) complexes of 3, 4, 5-trialkoxybenzoic acid-(2-hydroxy-4- alkoxybenzyidine)hydrazides; Series II dicopper (II) complexes of 4-(tetradecanoxybenzoicacid4-[(3, 4-dialkoxybenzoyl)hydrazonomethy] -3-hydroxyphenyl esters and Series III: 2, 6-bis-(3,4,5-trialkoxphenyl) benzo[1, 2-d; 5, 4-d’]bisoxazoles. By molecular modification of the carbon chain lengths, the number of the terminal flexible side chains and/or the linkers, the mesomorphic properties observed by these compounds were characterized and also studied in detail. For the spectroscopic characterization of all compounds, 1H and 13C NMR spectra were used to identify the structure and the purity of the compounds, and elemental analysis was also used to confirm the purity. DSC thermal analysis and optical polarised microscopy were used to characterize and confirm the structure of the liquid crystalline mesophases. The data indicated that for the Series I, dicopper (II) complexes of 3, 4, 5-trialkoxybenzoic acid-(2-hydroxy-4-alkoxybenzyidine)hydrazides, when the numbers of the terminal flexible side chains were either six or eight these copper complexes exhibited Colh phase. The Colh phases were observed for the Series II, dicopper (II) complexes of 4-(tetradeca noxybenzoic acid 4-[(3, 4-dialkoxybenzoyl)hydrazonomethy]-3-hydroxy phenyl esters with the ether group as linker, when the carbon numbers is six, however, the same Colh phases were also formed for the copper(II) complexes with ester group as linker and side chains of ten. For the series III, 2, 6-bis-(3,4,5-trialkoxphenyl)benzo[1,2-d; 5, 4-d’]bisoxazole, these compounds exhibited Colh phases when the carbon numbers of the terminal flexible side chains are 8, 10, 12 and 14 |
