Crystals liquid complex

Crawford, GP Zumer, S, eds. Liquid Crystals in Complex Geometries, Formed by Polymer and Porous Networks Taylor and Francis London, 1996. 

Depending on the R group, this reaction could lead to the formation of gold(I) isocyanide complexes that behave as liquid crystals. Thus, complexes [Au(C6F5) (C = N(QH4)OCioH2i-p)] and [Au(QF5)(C = N(QH4)OCnH2n + rP)] [64] where n = 4, 6, 8, 10 and 12 show this behavior. All of these complexes are mesomorphic and behave as liquid crystals showing a nematic (N) phase when the isocyanide has a... 

Both forms have been isolated in a number of cases [Eq. (90)]. The ionic component has been obtained when diphenylboryloxymethyl(oxy-methyl)phenylphosphine sulfide is treated with triethylamine or pyridine. In the case of pyridine the complex is isolated by careful evaporation of benzene solvent. Unlike the ionic form, which is crystalline, the complex form is a liquid. In its IR spectrum there is an intense absorption of the hydroxyl groups and no absorption of the H—N+ bond. Spectra of benzene solutions of the complex and ionic forms are identical. With crystallization the complex form rearranges into the ionic form. 

Milk fat is liquid above 40°C and completely solid below -40°C. Between these extremes it is a mixture of crystals and oil, with the latter a continuous phase. The nature of crystallization is complex because of the large number of TGs present. The properties of milk fat are the average of the properties of the TGs, and not necessarily those of the esterified fatty acids. 

Group 12 element liquid crystals, 12, 286 liquid crystals, 12, 217 Pd(II) and Pt(II), liquid crystals azo complexes, 12, 248 azoxy complexes, 12, 253... 

In this chapter we will review the recent advances of supramolecular photon chirogenesis in various confined media, excluding micelles, chiral solvents, liquid crystals, metal complexes, polymer matrices, clays, and crystals. Micelles are typical supramolecular assembly with an internal hydrophobic core which shows a unique boundary effect, e.g., enhanced radical recombination of geminate radi-cal pairs produced by ketone photolysis [26], but essentially no asymmetric photon-... 

A. A Brief Introduction to Liquid Crystals Liquid-Crystalline Metal Complexes of Alkoxystilbazoles... 

Fluid flow within the melt has a crucial effect on crystal quality. If the crystal is stationary, the dominant convection pattern is upward flow of material at the crucible walls and radial flow inward at the surface (type I). Rapid rotation of crystal causes material to be thrown radially outward at the surface, and opposes the thermal convective flow (type III). These flow patterns are shown in Figure 3. In the intermediate regime, where the two flows are of comparable rates, a more complex surface pattern is observed, labeled type II. The crystal-liquid interface is convex toward the melt in type I flow and planar in type II, a condition that is used for the growth of large crystals of gadolinium gallium garnet ... 

Leaver, D. J., Kralj, S., Sluckin, T. J., and Allen, M. P. (1996) Liquid Crystals in Complex Geometries Formed by Polymer and Porous Networks, ed. Crawford G. P., and Zumer S. (Oxford University Press London)... 

Recently an improvement in this separation technique was reported, which seemed to indicate that enantioselective inclusion in the lattices of chiral hosts could be employed on a large scale. [11] When crystalline hosts such as R,R)-(-)-S (m.p. 196 °C), [12] (/ ,/ )-(-)-9 (m.p. 165 °C), [12] and (5,5)-(-)-10 (m.p. 128 °C) are suspended in hexane or water, chiral guest molecules form the same inclusion compounds as from solution. This is by no means self-evident, since inclusion compounds have different crystal lattices than the pure host crystals. Thus crystal/liquid reactions occur, and phase rebuildings analogous to those observed in gas/solid reactions [13] must take place. Yet this suspension technique is more selective and more effective than the initially developed solution technique. Numerous racemic alcohols like 11, -hydroxy esters like 12, epoxy esters like 13, and epoxy ketones like 14 were stirred a few hours with appropriate hosts (suspensions of 8, 9, and 10) and formed 1 1 complexes that could be filtered off in yields of > 85 % and with ee values of > 97 % (the complex of 12 and 9 formed in hexane only 80% ee in one step). Recrystallization of the inclusion... 

Fig. 8.12 is an electron microscope photograph of aragnonite crystals (CaCO ) deposited from a flowing stream. It is possible to recognise a few smaller crystals of calcite (emother crystalline form of CaCO ) in among the larger crystals. The complexity of the solid surface presented to the flowing liquid is apparent. 

The melting behavior of miscible crystallizable blends (section 3.3.5) is often complex, revealing multiple DSC endotherms, which can be ascribed to several causes such as recrystallization, secondary crystallization, liquid-liquid phase separation (3.3.6), etc. 

Ion-selective membranes attain their permselectivity from ion-exchange, dissolution, or complexation phenomena. Different types of membranes are available for the construction of ion-selective electrodes glass and other solid state rods (crystals), liquid or polymer ion ecchangers, or dissolved ionophores. Many electrodes are commercially available with selec-tivities for different ions, mainly H, alkali metal cations, heavy metal ions, and halides or pseudohalides. Also gas-sensing electrodes may be constructed from an ion-selective electrode and a gas-permeable membrane [182]. Ion selective electrodes and gas-selective electrodes... 

Keywords Hydrogen bonding. Liquid crystal. Liquid crystal polymer. Self-assembly, Selforganization, Complex, Gel, Supramolecular chemistry... 

M. Vilfan, N. Vrbancic-Kopac Nuclear magnetic resonance of liquid crystals with an embedded polymer network. In Liquid Crystals in Complex Geometries, ed by G.P. Crawford, S. Zumer (Taylor Ftancis, London 1996) chap 7. 

G. P. Crawford and S. Zumer, Edts., Liquid Crystals in Complex Geometries, Taylor Francis, London, (1996). 

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