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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/5905

    Title: 含單金屬桿狀無機液晶之設計與探討;The study of metallomesogen
    Authors: 徐彥皇;Yen-Huang Hsu
    Contributors: 化學研究所
    Keywords: 液晶;metallomesogen
    Date: 2002-06-31
    Issue Date: 2009-09-22 10:10:02 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 摘 要 本實驗主要是研究含金屬中心之無機液晶的設計與探討。藉由改變柔軟長碳鏈的長度,來觀察其液晶相的形成與否。本實驗所合成之化合物藉由1H-與13C-NMR光譜及元素分析(EA)來鑑定分子的結構與純度。液晶現象的觀察是藉由偏光顯微鏡(polarizing optical microscopy)來觀察其光學紋理圖,再以熱差式掃描卡計儀(differential scanning calorimetry)測定其相變化時之熱焓值變化,最後以變溫粉末X光繞射儀(temperature-dependent X-ray diffraction)鑑定其液晶相的結構。 系列一成功的合成出一系列Schiff base形式的diimine配位基,此配位基再與Cu(II)進行配位,形成錯合物。實驗結果顯示配位基呈現了液晶相,其液晶相為SmC及N相。錯合物側鏈基alkoxy group碳數n為10、12、14、16時呈現了SmC及SmA相。而配位基液晶相的範圍比錯合物大了約100℃。 系列二合成了一系列以pyrazole 分子為配位基與PdCl2 配位而形成無機盤狀液晶。實驗中我們發現當配位基之側鏈基數目越多時(即推電子基越多),較能利用pyrazole 分子氮上的lone pair 來和Pd 金屬配位,所以只有側鏈基總數為五的pyrazole 分子能得到較高產率的Pd錯合物,其中錯合物側鏈基alkoxy group碳數n為12時呈現了結晶相,n為14和16時呈現了Colho相。 Abstract Transition metal complexes of Schiff bases derived from salicyladimines are among the best known of complexes that exhibited mesogenic properties in metallo mesogenic structures. A variety of transition metals, such as Fe, Rh, Ir, VO, Ni, Co, Cu, Pt, Pd etc. forms novel mesomorphism with salicyladimine Schiff bases. The overall molecular shapes of these complexes derived from salicyladimines were more likely of rod-like or brick-like shapes with two or four extended flexible sidechains, and these complexes all exhibited nematic or smectic phases predominantly, regardless of the metal center incorporated in such systems. Difference in the mesogenic properties of these Schiff base metal complexes was attributed to the various types of geometric coordination of the metal centers. In this work the synthesis and mesomorphic properties of a homologous series of N-(2-hydroxy-4-n-alkoxylbenzylidene)-4-n-alkoxyl phenylanilines and their copper(II) complexes are reported. These rod-like copper(II) complexes exhibited smectic and nematic phases, as predicted for rod-like molecules. Their mesomorphic properties were characterized by DSC thermal analysis, optical polarized microscopy and powder XRD diffraction. All salicyladiminato ligands and their copper(II) complexes exhibited enantiotropy phases. The compounds of ligands showed smectic C (SmC) and nematic (N) phase and copper(II) complexes formed SmC and smectic A (SmA) phases. The difference in formation of mesophases was due to the molecular shape variation. In addition, copper complex with two hexadecyloxy (n=C16) group as sidechains have a widest temperature range of the SmC mesophase. The mesomorphic properties of these copper(II) complexes were also compared with other similar metallomesogenic bis(salicyladiminato)- copper(II) complexes in terms of molecular structures.
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