Functional π-Gelators and Their Applications

In the 21st century, soft materials will become more important as functional materials because of their dynamic nature. Although soft materials are not as highly durable as hard materials, such as metals, ceramics, and engineering plastics, they can respond well to stimuli and the environment. The introduction of order into soft materials induces new dynamic functions. Liquid crystals are ordered soft materials consisting of self-organized molecules and can potentially be used as new functional materials for electron, ion, or molecular transporting, sensory, catalytic, optical, and bio-active materials. For this functionalization, unconventional materials design is required. Herein, we describe new approaches to the functionalization of liquid crystals and show how the design of liquid crystals formed by supramolecular assembly and nano-segregation leads to the formation of a variety of new self-organized functional materials.

Functional liquid-crystalline assemblies: self-organized soft materials.

Department of Chemistry, Department of Radiology, Washington University in Saint Louis, Saint Louis, Missouri 63130, Department of Chemistry, Texas A&M University, College Station, Texas 77842, Cancer Center Karolinska, Department of Oncology-Pathology CCK, R8:03 Karolinska Hospital and Institute, SE-171 76 Stockholm, Sweden, and Department of Chemistry and Biochemistry, Department of Materials, and Materials Research Laboratory, University of California, Santa Barbara, California 93106

/pdf/applications-of-orthogonal-click-chemistries-in-the-3vuh4s7zls.pdf

Applications of Orthogonal “Click” Chemistries in the Synthesis of Functional Soft Materials

The potential of palladacycles: more than just precatalysts

Ionic liquid crystals.

A ferroelectric liquid crystal dimer: Synthesis and properties†

In this tutorial review we describe some studies concerning liquid crystal dendritic polymers. We have chosen to present several representative examples that illustrate the diverse kinds of LC dendritic structures, namely: dendrimers, dendrons, dendronized polymers and hyperbranched polymers. We review their synthesis, mesogenic properties and the way that they are arranged to form supramolecular liquid crystal assemblies.

Highly congested liquid crystal structures: dendrimers, dendrons, dendronized and hyperbranched polymers.

A new series of liquid crystalline poly(amidoamine) (PAMAM) dendrimers is described. These dendrimers are made by attaching to the 0-, 1-, 2-, 3-, and 4-generation of PAMAM-terminal promesogenic units that carry two decyloxy chains in the 3- and 4-positions of their peripheral aromatic ring. X-ray diffraction studies show that all the compounds display a hexagonal columnar mesophase. A high density of aliphatic chains imposes a curved interface with the promesogenic units that forces the molecules to adopt a radial conformation, and therefore, the columnar structure. A model for the supramolecular organization of the different generations within the columnar mesophase is proposed based on the variation of some of the structural parameters.

Dendromesogens: Liquid Crystal Organizations of Poly(amidoamine) Dendrimers versus Starburst Structures

Poly(amidoamine) starburst dendrimers which contain peripheral mesogenic ester units were found to exhibit a smectic A mesophase. A structural model is proposed that is valid for several generations of dendrimers. The mesogenic units form parallel aggregations that give rise to the smectic structure (shown schematically).

Dendromesogens: Liquid Crystal Organizations versus Starburst Structures

The synthesis and characterization of two families of ionic liquid crystal dendrimers consisting of the ammonium salts of the commercially available poly(amidoamine) (G = 0-5) and poly(propylene imine) (G = 1-5) dendrimers and three long-chain carboxylic acids are reported. The liquid crystalline behavior was investigated by means of differential scanning calorimetry, polarizing light optical microscopy, and X-ray diffractometry. The thermal stability of the ionic materials was further studied by NMR. Most of the dendrimers show lamellar mesomorphism, and two of them exhibit columnar mesomorphism. On the basis of the experimental results, we propose models both at the molecular level and in the mesophase for all the materials.

Mercedes Marcos

Papers

A ferroelectric liquid crystal dimer: Synthesis and properties†

Highly congested liquid crystal structures: dendrimers, dendrons, dendronized and hyperbranched polymers.

Dendromesogens: Liquid Crystal Organizations of Poly(amidoamine) Dendrimers versus Starburst Structures

Dendromesogens: Liquid Crystal Organizations versus Starburst Structures

Ionic thermotropic liquid crystal dendrimers.