Ferroelectric nematogens containing a methylthio group
Ferroelectric nematogens containing a methylthio group
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含有甲硫基的铁电线虫
DOI：
10.1039/d3ma00446e
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发表时间：
2023
影响因子：
5
通讯作者：
Stepanafas G
中科院分区：
文献类型：
--
作者：
Stepanafas G
本文报道了八种末端含甲硫基的硫醚类化合物的合成和表征。这些化合物基于RM 734，氟取代基的数量和位置以及侧甲氧基取代基的位置不同。这些化合物中的七种表现出单变铁电性铁电相NF，包括NF-各向同性相变的实例。两个化合物显示反铁电NX相。它们的过渡行为进行了讨论，在分子的形状和电子性质的变化。它们的相行为与含有末端甲氧基的相应化合物的相行为相似，但甲氧基封端的材料始终显示出较高的转变温度。这是占较大的减少与甲硫基的分子形状各向异性，以及相关的电子性质的变化。对于甲硫基取代的化合物观察到的NX相被认为反映了甲硫基对NF相的抑制，而不是任何特定的稳定作用。甲硫基之间的特定相互作用被认为是稳定的行为没有出现稳定的NF相。
The synthesis and characterisation of eight nematogens containing a terminal methylthio group is reported. The compounds are based on RM734 and differ in the number and position of fluorine substituents, and in the position of the lateral methoxy substituent. Seven of these compounds exhibit a monotropic ferroelectric nematic phase, NF, including examples of NF-isotropic phase transitions. Two of the compounds show the anti-ferroelectric NX phase. Their transitional behaviour is discussed in terms of molecular shape and changes in electronic properties. Their phase behaviour is similar to that of the corresponding compounds containing a terminal methoxy group, but the methoxy terminated materials consistently show the higher transition temperatures. This is accounted for by the larger reduction in molecular shape anisotropy associated with the methylthio group, and the associated change in the electronic properties. The NX phase seen for the methylthio substituted compounds are thought to reflect the suppression of the NF phase by the methylthio group rather than any specific stabilising effect. Specific interactions between methylthio groups thought to stabilise nematic behaviour do not appear to stabilise the NF phase.