Molecular control of macroscopic cubic, columnar, and lamellar organizations in luminescent lanthanide-containing thermotropic liquid crystals.
Molecular control of macroscopic cubic, columnar, and lamellar organizations in luminescent lanthanide-containing thermotropic liquid crystals.
复制标题
DOI：
10.1021/ja0446101
复制
发表时间：
2005-01
影响因子：
15
通讯作者：
E. Terazzi;S. Torelli;G. Bernardinelli;J. Rivera;J. Benech;C. Bourgogne;B. Donnio;D. Guillon;D. Imbert;J. Bünzli;André Pinto;D. Jeannerat;C. Piguet
中科院分区：
文献类型：
--
作者：
E. Terazzi;S. Torelli;G. Bernardinelli;J. Rivera;J. Benech;C. Bourgogne;B. Donnio;D. Guillon;D. Imbert;J. Bünzli;André Pinto;D. Jeannerat;C. Piguet
亲脂性没食子酸衍生物在刚性2，6-双（1-乙基-苯并咪唑-2-基）吡啶核的5，5 '-或6，6'-位的连接提供了两个前介晶三齿配体L10和L12，其分子形状、不对称性和定向分子间π堆积可以调节。结晶态的X射线衍射数据和溶液~ 1H NMR测量结果表明，与三价镧系元素Ln（III）配位生成中性半盘状配合物[Ln（Li）（NO3）3]（i = 10，12），在较低温度下二聚生成棒状双金属配合物[Ln_2（Li）_2（NO3）_6]。后一个过程的相关热力学参数取决于配体的性质、金属离子的大小以及凝聚相中所涉及的分子间相互作用的强度。这些三维模型中获得的晶体和溶液中的配合物最终面临的小角度的XRD曲线记录在中间热致液晶相，其中保持刚性的包装聚芳核，而烷基链是熔融的。根据分子配合物的几何构型和核性，可以诱导出三种类型的介晶相（层状、柱状和立方相），这为含镧系元素的金属介晶的微观排列和宏观有序性提供了直接的联系。
The connection of lipophilic gallic acid derivatives at the 5,5'- or 6,6'-positions of the rigid 2,6-bis(1-ethyl-benzimidazol-2-yl)pyridine core provides two pro-mesogenic tridentate ligands L10 and L12, whose molecular shapes, anisometries, and directional intermolecular pi-stacking can be tuned. X-ray diffraction data in the crystalline state, combined with solution 1H NMR measurements, show that complexation with trivalent lanthanides, Ln(III), produces the neutral hemi-disklike complexes [Ln(Li)(NO3)3] (i = 10, 12), which dimerize to give the rodlike bimetallic complexes [Ln2(Li)2(NO3)6] at lower temperature. The relevant thermodynamic parameters for the latter process depend on the nature of the ligand, the size of the metal ion, and the strength of the intermolecular interactions involved in the condensed phase. These three-dimensional models obtained for the complexes in the crystals and in solution are eventually confronted with small-angle XRD profiles recorded in the intermediate thermotropic liquid crystalline phase, in which the rigidity of the packed polyaromatic cores is maintained, while the alkyl chains are molten. According to the specific geometries and nuclearities of the molecular complexes, three types of mesophases (lamellar, columnar, and cubic) can be induced, which provides a direct correlation between the microscopic arrangements and the macroscopic ordering in lanthanide-containing metallomesogens.