Structure of a monolayer of molecular rotors on aqueous subphase from grazing-incidence X-ray diffraction
Structure of a monolayer of molecular rotors on aqueous subphase from grazing-incidence X-ray diffraction
复制标题
DOI：
10.1073/pnas.1712789115
复制
发表时间：
2018-09-18
影响因子：
11.1
通讯作者：
Michl, Josef
中科院分区：
文献类型：
--
作者：
Kaleta, Jiri;Wen, Jin;Michl, Josef
原位擦入射x射线散射表明，在Langmuir槽中水亚相表面产生的单层人工杆状偶极分子转子具有有利于形成二维铁电相的结构。转子的轴线在三角形网格中平均相距0.83 nm，垂直于实验误差范围内的表面。它们在靠近杆中心的地方携带2,3-二氯苯旋转器，在两层互锁的三环之间轴向安装在转子轴上。分析首先基于同时拟合观察到的布拉格棒，其次是拟合只有三个可调参数的反射率曲线和计算出的转子电子密度，这也揭示了每个转子附近大约有7个水分子。根据制备条件，在单分子层中也可以存在少量和可变量的不同晶体相。
In situ grazing-incidence X-ray scattering shows that a monolayer of artificial rod-shaped dipolar molecular rotors produced on the surface of an aqueous subphase in a Langmuir trough has a structure conducive to a 2D ferroelectric phase. The axes of the rotors stand an average of 0.83 nm apart in a triangular grid, perpendicular to the surface within experimental error. They carry 2,3-dichlorophenylene rotators near rod centers, between two decks of interlocked triptycenes installed axially on the rotor axle. The analysis is based first on simultaneous fitting of observed Bragg rods and second on fitting the reflectivity curve with only three adjustable parameters and the calculated rotor electron density, which also revealed the presence of about seven molecules of water near each rotator. Dependent on preparation conditions, a minor and variable amount of a different crystal phase may also be present in the monolayer.