Ion-based liquid crystal

Ion-Based Liquid Crystals From Well-Defined Self-Organized Nanostructures to Applications... 

Liquid-solid distributions are involved in ion-exchange and other adsorption-based separation processes, separation processes based on crystallization or precipitation, flotation processes for ore dressing, and smelting processes. 

The present chapter will not deal with general topics of liquid crystals or crown ethers as this exceeds the scope of this volume. Interesting reviews and monographs on liquid crystals and their properties can be found in the literature [10-13]. The synthesis of crown ethers can be challenging. Most commonly, the synthetic routes are based on procedures established by Pedersen [14-17]. A review by Bradshaw [18] and a monograph edited by Patai [19] also cover the synthesis and properties of crown ethers. More recent reviews deal with the use of crown ethers as chemosensors [20, 21], potential antitumor agents [22], molecular wires [23], or carriers for the separation of metal ions in liquid membrane processes [24],... 

Metal-based ionic liquid crystals containing a tetrahedral tetrahalometalate ion (MX X = Cl, Br, I M = Co, Ni, Cu, Pd, etc.) 7 [41, 54] and 8 [55-57] were studied (Figure 25.1). They provide various coordination geometries. For example, Al-aUcylpyridinium salts 8 often denoted as [C Py]2[CuCl4] (n= 12-18) show a variety of liquid crystalline phases from smectic to columnar or even cubic phases... 

In this chapter we have described the mesomorphic behavior and ionic conductivities of ionic liquid-based liquid crystalline materials. These ion-active anisotropic materials have great potentials for applications not only as electrolytes that anisotropically transport ions at the nanometer scale but also as ordered solvents for reactions. Ionic liquid crystals have also been studied for uses as diverse as nonliner optoelectronic materials [61, 62], photoluminescent materials [78], structuredirecting reagents for mesoporous materials [79, 80] and ordered solvents for organic reactions [47, 81]. Approaches to self-organization of ionic liquids may open a new avenue in the field of material science and supramolecular chemistry. 

F nmr spectra have been reported for tetrafluoro-l,3-dithietane in solution with nematic liquid crystals D2h symmetry is imputed. " Theoretical calculations of the transition energies and intensities of three different tetraalkyl-1,3-dithietanes indicate a need for the inclusion of d orbitals. Theoretical calculations also have been made on a dimer of 1,3-dithietane. The UV spectrum of 2,2,4,4-tetrachloro-1,3-dithietane has been interpreted with the aid of molecular orbital calculations, interaction between the two sulfur atoms is suggested. The photoelectron spectra of tetrafluoro and tetrachloro-l,3-dithietane and 1,3-dithietane itself have been reported. The negative-ion mass spectrum of tetra-fluoro-1,3-dithietane has a base peak corresponding to fluoride ion the base peak of tetra(trifluoromethyl)-l,3-dithietane corresponds to the anion of hexafluoro-thioacetone. The oxidation potential of 1,3-dithietane does not show any unusual transannular interactions in the cation radical. ... 

Ionic Liquid Crystals Based on Metal Ions... 

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