Solution-phase behavior

Solids can be crystalline, molecular crystals, or amorphous. Molecular crystals are ordered solids with individual molecules still identihable in the crystal. There is some disparity in chemical research. This is because experimental molecular geometries most often come from the X-ray dilfraction of crystalline compounds, whereas the most well-developed computational techniques are for modeling gas-phase compounds. Meanwhile, the information many chemists are most worried about is the solution-phase behavior of a compound. 

In neither case - Cr(CN-[P])g or Ni(CN-[P])4 - was a cyclic voltammetric response observed directly for the metal center at a Pt electrode, for either solution phase or surface-confined materials. The solution phase behavior in this respect is very similar to the situation encountered with many biological macromolecules (23). 

R Hansson and M. Akngren Interaction of Alkyltrimethylammonium Surfactants with Polyacrylate and Poly(Styrenesulfonate) in Aqueous Solution Phase Behavior and Surfactant Aggregation Numbers. Langmuir 10, 2115 (1994). 

While structures in the solid state do not necessarily parallel those in solution, they have been used to explain solution-phase behavior where other evidence is not available. For example, the conformation of the isopropyl groups in the highly substituted pyridine 16 in the solid state is as shown, as a result of the substituents adjacent on the ring <2004JOC536>. This was used to account for the greatly reduced nucleophilicity of this species. 

Gemini Surfactants Synthesis, Interfacial and Solution-Phase Behavior, and Applications, edited by Raoul Zana and Jiding Xia... 

The surfactant AOT forms reverse micelles in non-polar fluids without addition of a cosurfactant, and thus it is possible to study simple, water/AOT/oil, three component systems. To determine micelle structure and behavior in water/AOT/oil systems, investigators have studied a wide range of properties including conductivity (15), light (JL ), and neutron (12) scattering, as well as solution phase behavior (1 ). From information of this type one can begin to build both microscopic models and thermodynamic... 

The results from aqueous solution phase behavior studies show that phase separation takes place only when aqueous solutions are liquid crystalline. A schematic of a lamellar phase is shown in Figure 9. For the lamellar structure of the systems investigated, the bilayer thickness is about 10 to 30 °A while the thickness of the brine layer does not exceed 100 to 200 °A. Hence, the size of the polymer molecule is too large to be accommodated into the brine spacing in lamellar structure. 

Surfactant solution phase behavior is strongly affected by the salinity of the brine. In general, increasing the salinity of the brine decreases the solubility of the anionic surfactant in the brine. The snrfactant is driven out of the brine as the electrolyte concentration increases. Fignre 7.3 shows that as the salinity is increased, the surfactant moves from the aqneons phase to the oleic phase. At a low salinity, the typical snrfactant exhibits good aqueous-phase solubility. The oil phase, then, is essentially free of snrfactant. Some oil is solubilized in the cores of micelles. 

Hansson P, Almgren M. Interaction of alkyltrimethylammonium surfactants with poly(acrylate) and poly(styrenesulfonate) in aqueous solution. Phase behavior and surfactant aggregation numbers. Langmuir 1994 10 2115-2124. 

Thermodynamic Modeling of Supercritical Fluid-Solute Phase Behavior... 

The discussion above can be simply summarized to say that solution phase behavior is much more complex than pme component solid-liquid-gas phase behavior because the interparticle interactions have a much greater variety. The effective interparticle interaction in solution can have ... 

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