螺旋形态的共存在星形盘状水区的柱状堆中
Jie Shu1, Dmytro Dudenko, Morteza Esmaeili
1Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Journal of the American Chemical Society
|July 9, 2013
概括
迪斯科式水子分子形成具有六角柱状组织的液晶 (LC) 阶段. 复杂的晶体相显示了螺旋堆叠形态,受氧链长度的影响,表明有机电子的潜力.
科学领域:
- 材料科学 材料科学 材料科学
- 有机化学 有机化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 迪斯科提分子由于分子内键而表现出独特的迪斯科提液晶 (LC) 阶段.
- 这些分子具有刚性核心和灵活的外围氧链,影响它们的自我组装和相位行为.
研究的目的:
- 为了研究不同氧链长度 (六,八和十个碳) 的磁盘酸衍生物的热热态行为和固态组织.
- 阐明液晶和晶体相中的分子包装和堆叠形态.
主要方法:
- 二维广角X射线散射 (2DWAXS) 用于相位识别和结构分析.
- 广角X射线散射 (WAXS) 和先进的固态核磁共振 (SSNMR) 用于详细的固态结构确定.
- 支持结构建模和分析的初始计算.
主要成果:
- 这三种化合物都表现出六角柱状 (Colh) 液晶相,在高温下具有非倾斜的圆盘.
- 在25°C观察到具有六个和十个碳氧链的化合物复杂的结晶相,具有刚性柱和灵活的侧链.
- 同时存在的螺旋柱状堆叠形态与明显的倾斜/斜率角度被建模,显示对氧链长度的依赖.
结论:
- 醇基侧链的长度显著影响了晶体柱状相中的包装和倾斜/倾斜角度.
- 在柱状液晶中观察到的复杂的包装形态是罕见的,并突出了类似有机系统中复杂结构的潜力.
- 这些发现表明磁盘衍生物作为有机电子应用的潜在材料的实用性.
相关概念视频
02:11Conformations of Cyclohexane
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
02:33Stereoisomerism of Cyclic Compounds
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
02:02Chair Conformation of Cyclohexane
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
02:30Stability of Substituted Cyclohexanes
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
01:18Aromatic Hydrocarbon Anions: Structural Overview
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous overlap of p...
Due to the absence of continuous overlap of p...
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
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