Ionic liquid crystals (ILCs) are a class of materials that combine the properties of liquid crystals (LCs) and ionic liquids (ILs). This type of materials is directed towards properties such as conductivity in ordered systems at different temperatures. In this work, we synthesize five new families of ILCs containing symmetrical and unsymmetrical substituted pyrazolium cations, with different alkyl long-chains, and anions such as Cl−, BF4−, ReO4−, p-CH3-6H4SO3− (PTS) and CF3SO3− (OTf). We study their thermal behavior by polarized light optical microscopy (POM) and differential scanning calorimetry (DSC). All of them, except those with OTf as counteranion, show thermotropic mesomorphism. The observations by POM reveal textures of lamellar mesophases. Those agree with the arrangement observed in the X-ray crystal structure of [H2pzR(4),R(4)][ReO4]. The nature of the mesophases is also confirmed by variable temperature powder X-ray diffraction. On the other hand, the study of the dielectric properties at variable temperature in mesomorphic (Cl− and BF4−) and non-mesomorphic (OTf) salts indicates that the supramolecular arrangement of the mesophase favors a greater ionic mobility and therefore ionic conductivity.
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机译:离子液晶(ILC)是组合液晶(LCS)和离子液体(ILS)的性质的一类材料。这种类型的材料被引导至不同温度下有序系统中的电导率的性质。在这项工作中,我们合成包含对称和不对称取代的吡唑鎓阳离子的五种新的ILC系列,其具有不同的烷基长链,以及Cl-,BF4-,REO4-,P-CH3-6H4SO3-(PTS)和CF 3 SO 3的阴离子 - (otf)。我们通过偏振光光学显微镜(POM)和差示扫描量热法(DSC)来研究它们的热行为。所有这些,除了具有OTF作为抵抗的人,显示热致态二聚体。 POM的观察结果揭示了层状蛋白酶的纹理。那些与在[H2PZR(4),R(4)] [REO4]的X射线晶体结构中观察到的那些。通过可变温度粉末X射线衍射还证实了中间蛋白酶的性质。另一方面,在中间形(Cl-和BF4-)和非膈肌(OTF)盐中的可变温度下的介电性质的研究表明中间相的超分子布置有利于更大的离子迁移率并因此具有离子电导率。
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