Addition reaction of mesomorphic malonate-based dendrimers (up to the fourth generation) with C-60 gave liquid-crystalline fullerene derivatives. The cyanobiphenyl unit was used as liquid-crystalline promoter. The malonates presented nematic and/or smectic A phases. The fullerenes showed only smectic A phases, with the exception of the second generation dendrimer for which smectic A and nematic phases were observed. The supramolecular organization of the fullerene-based molecular units within the smectic A layers was investigated by X-ray diffraction. Two structural regimes were determined. For the low generation dendrimers, the supramolecular organization is determined by steric factors. For the high generation dendrimers, the mesogenic groups impose a microphase organization: due to lateral extension of the branching part of the molecule, the cyanobiphenyl groups arrange in a parallel fashion as in classical smectic A phases, the rest of the macromolecule being located between the mesogenic sublayers.
Detailed thermodynamic studies show that the dimeric complexes result from the formation of primary intermetallic nitrate bridges whose strength depends on the metallic size. For each complex, secondary nonspecific interstrand van der Waals interactions produce nonartifactual enthalpy/entropy compensation. In the absence of solvent, only the complexes with the most extended ligands L5 and L6 produce thermotropic
An all-liquid crystal based high-performance laser protection system <i>via</i> linear/nonlinear dual-mechanisms
作者:Wanshu Zhang、Lanying Zhang、Le Zhou、Jingxuan Zhang、Fasheng Li、Kexuan Li、Huai Yang
DOI:10.1039/c7cc05250b
日期:——
An all-liquid crystal based laser protection system based on mesogenic [60]fullerences and CLCs is reported that integrates an excellent optical limiting response, a broadband protection range, and good practicability simultaneously.
Thermodynamics of dimerization in solution as a rational tool for inducing nematic vs. smectic organizations in lanthanidomesogens
作者:Thomas B. Jensen、Emmanuel Terazzi、Bertrand Donnio、Daniel Guillon、Claude Piguet
DOI:10.1039/b714861e
日期:——
The judicious tuning of simple thermodynamic parameters controlling dimerization processes in solution induces a rational switch between smectic and nematic organizations in thermotropic lanthanide-containing liquid crystals.
明智地调整控制溶液中二聚过程的简单热力学参数会导致热致稀土液晶中近晶组织和向列组织之间的合理转换。
Functional polypedes—chiral nematic fullerenes
作者:Stéphane Campidelli、Carine Eng、Isabel M. Saez、John W. Goodby、Robert Deschenaux
DOI:10.1039/b303798n
日期:——
Self-organising, functional materials created by bottom-up synthesis represent important steps forward in the development of novel materials, here we report on the preparation and properties of a chiral nematic tetrapedal liquid crystal that has been functionalised with C60.
A liquid-crystalline fullerene–oligophenylenevinylene dyad which displays columnar mesomorphism
作者:Thi Nhu Y Hoang、Damian Pociecha、Miroslaw Salamonczyk、Ewa Gorecka、Robert Deschenaux
DOI:10.1039/c1sm05044c
日期:——
The design, synthesis and liquid-crystalline properties of a family of hybrid compounds which are built from rod-like (oligophenylenevinylene) and disc-like [poly(benzyl ether)] units are reported. All compounds form columnar phases within broad temperature ranges; the mesophases are stable even below room temperature. Weak photovoltaic effect was observed for the C60–OPV dyad. For the molecule having