Polycyclic Aryl Polysiloxane Synthesis And Applications In Capillary Gas Chromatography

At first the synthesis of a various of aryl-substituted cyclopentadienones are studied.Aryl-substituted cyclopentadienones were studied long ago.The benzoins, synthsised from the aromatic aldehydes,change to benzils through catalyzed oxidation.Then the benzils react with aryl- substituted ketones or alkyl- substituted ketones to form the aryl-substituted cyclopentadienones with one or two steps.But much attention were payed to the all aryl-substituted cyclopentadienones,few people studied the part aryl-substituted cyclopentadienones.The author synthesises a serious of aryl-substituted cyclopentadienones with the former researcher methods,such as 2,3,4,5-tetraphenylcyclopenta-2,4-dienone(Ⅰ),3,4-bis(4-methoxyphenyl)- 2,5-diphenylcyclopenta-2,4-dienone(Ⅱ),3,4-di(furan-2-yl)-2,5-dimethyicyclopenta-2, 4-dienone(Ⅲ),7,9-diphenyl-6bH-bicyclo[3.2.0]hepta-1(5),1,4-trieno[6,7-a]-acenaphthylen-8 (9bH)-one(Ⅳ),2,5-dimethyl-3,4-diphenylcyclopenta-2,4-dienone (Ⅴ),3,4-diphenylcyclopenta-2,4-dienone(Ⅵ),2-methyl-3,4-diphenylcyclo-penta-2, 4-dienone(Ⅶ),2-ethyl-3,4-diphenylcyclopenta-2,4-dienone(Ⅷ).They are all analysed with H-NMR and IR.The compounds(Ⅵ),(Ⅶ)and(Ⅷ)are first peported in literature.2,3,4,5-Tetraphenylcyclopenta-2,4-dienone(Ⅰ)is choosed to react with vinyl polysiloxane to form tetraphenyl phenyl polysiloxane through Diels-Alder reaction. After purification the product is coated on fused silica capillary columns with static method.Chromatographic properties like selectivity,polarity,separation efficiency, inertness,bleeding and so on of the capillary were evaluated,especially the selectivity of aromatic hydrocarbon such as substitutes of benzene,polycyclic aromatic hydrocarbon(PAH).The investigation reveals that the fused silica capillary columns coated with tetraphenyl phenyl polysiloxane posseses superior separation efficiency(no less than 4000 P/m)and high intemess.It belongs to medium polar stationary phase(the constant of overall polarity is 737),the maximum allowable operating temperature is 330℃.The separation of the liquid paraffin,coal tar and polycyclic aromatic hydrocarbon confirms that tetraphenyl phenyl polysiloxane stationary phase has superior separation efficiency to alkanes and aromatic hydrocarbon compounds.It is significative to study the polysiloxane with polycyclic aromatic group.