论文标题
分子间相互作用在稳定列旋转相结构中的作用
The role of intermolecular interactions in stabilizing the structure of the nematic twist-bend phase
论文作者
论文摘要
分子结构与NTB相的形成之间的关系仍处于发展的早期阶段。这主要与分子几何形状有关，而NTB相和电子结构之间的相关性模棱两可。为了探索对NTB期性能的电子影响和稳定，我们研究了2,3-二氟-4,4-二苯基 - 二苯基二苯基二聚体（DTC5CN）。我们使用了IR极化光谱法，至少可以原则上可以带来有关NTB相中订购的信息。所有二聚体在过渡到NTB相的平行偶极子的过渡偶极矩Dμ/dq的平均值的显着下降，尽管其单体仍保持不变，但垂直偶极子的平均值显着下降。这些结果与在NTB相中组装的分子的振动偶极衍生物的DFT模拟很好地一致。 DFT计算用于确定氢键复合物的几何和电子特性。我们提供了通过多个氢键（XF ... HX，X-苯甲环）的阵列稳定NTB相的实验和理论证据。
The relationship between the molecular structure and the formation of the NTB phase is still at an early stage of development. This is mainly related to molecular geometry, while the correlation between the NTB phase and the electronic structure is ambiguous. To explore the electronic effect on properties and stabilization of the NTB phase we investigated 2,3-difluoro-4,4-dipentyl-p-terphenyl dimers (DTC5Cn). We used IR polarized spectroscopy, which can at least in principle, bring information about the ordering in NTB phase. All dimers show a significant drop of the average value of the transition dipole moment dμ/dQ for parallel dipoles at the transition to the NTB phase, and an increase for perpendicular dipoles, despite its remaining unchanged for the monomer. These results coincide well with DFT simulations of vibrational dipole derivatives for molecules assembled in pseudo-layers of the NTB phase. The DFT calculations were used to determine the geometric and electronic properties of the hydrogen bonded complexes. We have provided experimental and theoretical evidence of stabilization of the NTB phase by arrays of multiple hydrogen bonds (XF...HX, X-benzene ring).
