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Abstracts Of Project Papers

Determination Of Mechanisms Via Computational Chemistry For Xylene And Hydroxynaphthalene Separations On Beta-Cyclodextrin

Static and dynamic separations for the three xylene and two hydroxylnaphthalene (naphthol) isomers were experimentally obtained with beta-cyclodextrin (beta-CD) on mesoporous glass bead and silica gel supports. Beta-CD/support attachment was either by direct covalent bonding or through tethering with 3-glycidoxypropyltrimethoxysilane. Obtained guest/host separation selectivity ratios were as high as 4.1/1.0 for 1-naphthol from 2-naphthol. Maximum separation ratios were 2.4/1.0 for m-xylene from p-xylene and 0.75/1.0 for o-xylene from p-xylene. Beta-CD tethering decreased the separation efficiencies of the xylene and naphthol isomers over those obtained by beta-CD covalent bonding. Molecular mechanics and semi-empirical methods were used to determine the mechanisms for the above guest/host separation efficiencies. The three mechanisms evaluated were guest/host inclusion energy, charge transfer and steric hindrance. Computational results show that steric hindrance of guest entering host was the controlling mechanism. Levels of steric hindrance were determined by guest/host overlap of electrostatic potential surfaces. A key component concept was used to develop a model for predicting separation selectivities for other guests with beta-CD and other guest/host combinations. This model is based on a linear correlation between component/key component selectivity ratios and component/key component electrostatic potential overlap ratios.


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Hydrocarbon Absorption In Molten Tetrachloroaluminates

Chemical Mechanisms In Hydrogen Sulfide Decomposition to Hydrogen and Sulfur

Solvent Effects In The Conversion of Anthraquinone to Antrahydroquinone and Simultaneously Hydrogen Sulfide to Hydrogen and Sulfur

Modeling The Folding and Hydrogen Production of Clostridium acetobutylicum and Clostridium saccharobutylium Mutants Using Electrostatic Potential Surfaces and Molecular Dynamics

Determination Of Mechanisms Via Computational Chemistry For Xylene And Hydroxynaphthalene Separations On Beta-Cyclodextrin

Development of a Liquid Extraction Process for Removal of Sulfur Compounds from Gasoline using Quantum/Molecular Mechanics Methods

Correlation of Rate and Michaelis Constants with Atomic Charge for the Dehydrogenation of Butyryl-CoA Derivatives Using Human Glutaryl-CoA Dehydrogenase

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