Guest complexes sorption

From sorption experiments the efficacy of a sorbate has been measured as heat of adsorption and described as nest effect , relating size and shape of the sorbate with the surface curvature of the pore [48]. Recently, host-guest complexes have been formulated quantitatively in terms of van der Waals interactions. Lewis et al. [47] calculated the nonbonded interactions energy of the SDA within the cavities of different silica zeoHtes, which was in good agreement with the experimental synthesis experience. The computational strategy developed in this study should stimulate the systematic search for new effective SDAs for the synthesis of new porosil structures with tailored pore geometry [49]. 

Sorption of guest molecules from the liquid phase may proceed either when the guest molecules form a liquid phase by themselves, or when they are dissolved in a suitable solvent (such as water, alcohol, or Me2SO). In the latter case, the kinetics of complexation can be monitored by spontaneous precipitation of the complex. Acceptable results are achieved when the... 

The limited solubility of starch and its modified products may affect the reversibility of many reactions. This may explain several, apparently unusual, reactions reported in starch chemistry. There are, for example, reports of starch esterification with sodium hydrogenphosphates, acylation of starch with acyl amides (which is equivalent to the transformation of an amide into an ester), and the formation of alkali-metal starchates upon treatment of starch with alkali (a reaction which fails for simple alcohols). A specific property of starch is its ability to form surface sorption and helical inclusion-complexes with many inorganic and organic guest molecules.4... 

Complexes of guest species with active sites in zeolite pores are formed during various processes such as characterization of the material, catalytic transformation, selective sorption, and separation [124,125]. A guest molecule adsorbed in a zeolite can in general be involved in several types of interactions ... 

The predominant importance of the cations in zeolites is that they form so-called active sites for selective interaction with guest molecules in sorption and catalytic processes. From the point of view of advanced material science [47] they play a significant role in the formation of quantum-sized clusters with novel optical or semiconducting properties. As they give rise to cationic conductivity, zeolites can be used as solid electrolytes, membranes in ion-selective electrodes and as host structures in solid-state batteries. Organometallic compounds and coordination complexes can be readily formed on these cations within the larger cages or channels and applied to gas separation, electron-transport relays and hybrid as well as shape-selective catalysis [48]. 

Self-assembled coordination poiymers containing transition metal ions and organic bridging ligands have attracted intensive interest because of their potentiai abiiities for selective inclusion and transformation of ions and molecules [I-4]. Construction of a variety of assembled structures plays an important role in designing the size and shape of vacancy. Both the variety of assembled structures and sorption of guest molecules can affect the properties of assembled complexes. 

The research on guest-inclusion complexes of calixarene based molecular crystals paved the way for different type of gas-sorption studies in these materials under various conditions. Although these materials generally dcai t possess uniform pore nor have high surface area (unlike traditional porous materials such as zeolite, molecular sieves or MOFs), their unique void structures make them attractive candidates for selective gas-sorption and separation applications. It should be noted that no uniform method were used to analyze the gas-sorption capacity (or separation capability) of these... 

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