当前位置: X-MOL 学术RSC Adv. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Fluorenone imidazolium salts as novel de Vries materials
RSC Advances ( IF 3.9 ) Pub Date : 2020-6-23 , DOI: 10.1039/d0ra04650g
Korinna Bader 1 , Carsten Müller 2 , Yann Molard 3 , Angelika Baro 1 , Philipp Ehni 1 , Jakob Knelles 1 , Sabine Laschat 1
Affiliation  

In ionic liquid crystals (ILCs) tilted mesophases such as SmC required for electro-optic devices are quite rare. We report a design concept that induced the SmC phase and enabled de Vries-like behaviour in ILCs. For this purpose, we synthesized and characterized a library of ILC derivatives ImR(On,Ym)X which consist of a rigid central fluorenone core containing an alkoxy or thioether side chain and connected via a flexible spacer to an imidazolium head group. The mesomorphic properties were studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XRD). Temperature-dependent measurements of smectic layer spacing d by small-angle X-ray scattering (SAXS) and of optical tilt angles by POM demonstrate that ILCs ImR(On,Ym)X undergo SmA–SmC phase transitions with maximum layer contraction values between 0.4% and 2.1%. The lowest reduction factor R of 0.2 at the reduced temperature TTAC = −10 K was calculated for Im(O12,S14)Br. Electron density calculations indicated a bilayer structure. Furthermore, temperature dependent emission studies show that self-assembling has a strong influence on the emission intensity of these ILCs.

中文翻译:

芴酮咪唑鎓盐作为新型德弗里斯材料

在离子液晶 (ILC) 中,电光器件所需的倾斜中间相(例如 SmC)非常罕见。我们报告了一个设计概念,它引发了 SmC 阶段并在 ILC 中启用了类似 de Vries 的行为。为此,我们合成并表征了 ILC 衍生物ImR(On,Ym)X库,该库由含有烷氧基或硫醚侧链的刚性中央芴酮核心组成,并通过柔性间隔物连接到咪唑头基团。通过差示扫描量热法(DSC)、偏光显微镜(POM)和X射线衍射(XRD)研究了介晶性质。近晶层间距d的温度相关测量通过小角 X 射线散射 (SAXS) 和 POM 的光学倾斜角表明 ILC ImR(On,Ym)X经历 SmA-SmC 相变,最大层收缩值在 0.4% 和 2.1% 之间。对于Im(O12,S14)Br ,在降低的温度T - T AC = -10 K 下计算的最低降低因子R为 0.2 。电子密度计算表明双层结构。此外,与温度相关的发射研究表明,自组装对这些 ILC 的发射强度有很大影响。
更新日期:2020-06-23
down
wechat
bug