Liquid guest molecules

X-ray Diffractometry and Single-Crystal X-ray Structure Analysis Liquid guest molecules have no diffraction pattern of their own, then there is a difference in the diffraction of newly formed complex and uncomplexed cyclodextrin, indicating the complex formation [57]. In the case of solid guest compound, the dif-fractogram of newly formed complex and mechanical mixture of guest and cyclodextrin molecule are compared [50]. 

This means that the partial molar area may directly be determined from the change in molecular area, when an amphiphilic molecule is introduced into a host liquid crystalline pattern. Of course, this area is the change of area per molecule at the introduction of one molecule of the substance in question and may be influenced by the interaction between the host molecules and the guest molecules. Since this interaction is an essential part of the present problem, it appears obvious that the method exactly meets the requirements. 

Immobilization. The ability of cyclodextrins to form inclusion complexes selectively with a wide variety of guest molecules or ions is well known (1,2) (see Inclusion COMPOUNDS). Cyclodextrins immobilized on appropriate supports are used in high performance liquid chromatography (hplc) to separate optical isomers. Immobilization of cyclodextrin on a solid support offers several advantages over use as a mobile-phase modifier. For example, as a mobile-phase additive, p-cyclodextrin has a relatively low solubility. The cost of y- or a-cyclodextrin is high. Furthermore, when employed in thin-layer chromatography (dc) and hplc, cyclodextrin mobile phases usually produce relatively poor efficiencies. 

Thus the boundaries of the enclosures in organized media may be of two types they may be stiff (i.e, none of the guest molecules can diffuse out and the walls do not bend), as in the case of crystals and some inclusion complexes, or flexible (i.e., some of the guest molecules may exit the cavity and the walls of the cavity are sufficiently mobile to allow considerable internal motion of the enclosed molecules), as in the case of micelles and liquid crystals. In these two extremes, free volume needed for a reaction is intrinsic (built into the reaction cavity) and latent (can be provided on demand). 

Thermal fluctuations cause a group of guest (CO2) molecules to be arranged in a configuration similar to that in the clathrate hydrate phase. The structure of water molecules around locally ordered guest molecules is perturbed compared to that in the bulk. The thermodynamic perturbation of the liquid phase is due to the finite temperature of the system. This process is stochastic. 

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