Containing Phenyl Carbosilane Dendrimer Silicone Key Stationary Phase Preparation And Performance Study

High Performance Liquid Chromatography (HPLC) has important roles in fields of analysis and separation of compounds. It can intercompensate with the Gas Chromatography for its high efficiency and mild operational conditions. Stationary phases based on porous silica chemically modified with organic compounds are the most widely used type in modern HPLC. Even some special problems such as analyses of enantiomers can be solved by means of chromatographic systems with reversed stationary phases. Most of progress in HPLC separations has been achieved due to the introduction of numerous silica-bonded stationary phase materials.Dendrimers are perfect monodisperse macromolecules with a regular and high branched three-dimensional architecture. High generations of dendrimers tend to adopt a sphere shape. Dendrimers has got wide attention during the last two decades and wide use in many fields as functional materials.The characteristics of silicone dendrimers are such that they provide the perfect balance of chemical properties such as chemical inertness, high fluidness in high molecular weight required by many of today's most demanding applications. These kinds of dendrimers ' main chain are comprised of Si-C, Si-O-Si or Si-Si bonds.Carbosilane dendrimer-bonded silica stationary phases were synthesized and characterized in this thesis.The first (G₁) and second (G₂) generations of carbosilane dendrimers with allyl end groups were synthesized using CH₃SiCl₃ as core, allylmagnesium chloride as alkylating agents. And this paper has refered to the purification of carbosilane dendrimer with allyl end groups.Then, G₁ and G₂ reacted with phenylmagnesium bromine, allylmagnesium chloride, ethylmagnesium bromine all convert to new kinds of silicone dendrimers with phenyl, allyl and ethyl end groups. All the dendrimers were characterized by IR and ¹H NMR Spectroscopy. The difference of phenylmagnesium bromine, allylmagnesium chloride, ethylmagnesium bromine are probed into. The control of humidity and temperature exert influence on Platinum-catalyzed hydrosilylation. Also the select of solvent has been discussed.Platinum-catalyzed hydrosilylation of allyl groups of G₂ and G₃ with CH₃HSiCl₂ was carried out, and then dendrimers were bonded to silica gel by the reactions of Si-Cl and Si-OH groups of the silica gel to get the dendrimer-bonded silica stionary phases. The carbosilane dendrimer-bonded silica gel was characterized by IR and Element Analysis. The results clearly show the experiment proceed successfully as designed.Result showed that the bonded-density of G₂ is 3.89μmol/m² and the bonded -density of G₃ is 2.06μmol/m². The reason may be larger bulk leading to more severity space steric hindrance.The carbosilane dendrimer-bonded silica gel was characterized by HPLC. All results clearly confirm the reactions occurred successfully as pre-designed. Carbosilane dendrimer-bonded silica gel as stationary phase has good separating performance. They are effective to separate enantiomers of alcohol, alkyl -substituted benzene, metacrylic acid ester and phthalate. Separating performances were compared between G₂ and G₃ stationary phases. The magnitude vacuum and the hydrophobic functional group are of advantage to the latter. Thereby the G₃ stationary phases has much better performance though lower bonded-density.