五炔苯衍生物之單體與雙聚物生成的筒型與盤狀向列型超分子結構

Columnar and Discotic Nematic Superstructures from Monomers and Dimers of Pentaynylbenzene Derivatives.

廖竟婷(Ching-Ting Liao)

指導教授 ： 徐秀福

淡江大學/理學院/化學學系碩士班/碩士(2007年)

https://doi.org/10.6846/TKU.2007.00672

摘要

系列一之化合物以外圍苯環具一條側鏈之五炔苯基苯化合物做衍生，改變第六個位置之官能基以了解其對原有之盤狀向列型液晶性質之影響。另外，以含過渡金屬鉑之單元作為架橋基連接兩個盤形單元，藉由在垂直於盤面調控分子間作用力達成降低相轉移溫度並增加液晶溫度範圍之結果。而含有過渡金屬鉑之單元的單體與雙聚物比原有機單體之液晶溫度範圍分別增加96 ℃與125 ℃。
系列二與系列一最大的差別為在五炔苯基苯上外圍五個環上各增加一條側鏈，側鏈的增多使凡得瓦力增大，鏈與鏈之間容易聚集且同時阻礙外圍炔苯基旋轉，使具高共軛特性的五炔苯基苯進行堆疊生成較有秩序性的筒型液晶相。此系列以外圍烷氧鏈碳數為八之單體化合物皆有很廣之液晶溫度範圍性質。然而其自身偶合雙聚物與含有過渡金屬鉑單元形成的雙聚物，則因兩盤體間之立體效應使筒型排列瓦解而不具液晶性質。

關鍵字

筒型液晶 ； 盤形向列形液晶 ； 鉑金屬 ； 限制旋轉 ； 盤形單元 ； 雙聚物

並列摘要

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.

並列關鍵字

restricted rotation ； π-π interactions ； columnar phase ； discotic nematic phase ； platinum ； side-arm

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