Show simple item record

dc.contributor.authorMcEleney, Kevinen
dc.date2009-04-20 10:49:13.443
dc.date.accessioned2009-04-22T17:31:55Z
dc.date.available2009-04-22T17:31:55Z
dc.date.issued2009-04-22T17:31:55Z
dc.identifier.urihttp://hdl.handle.net/1974/1763
dc.descriptionThesis (Ph.D, Chemistry) -- Queen's University, 2009-04-20 10:49:13.443en
dc.description.abstractMesoporous silicates are excellent materials for supported catalysis due to their ease of functionalization, tunable pore size and high surface areas. Mesoporous silicates have been utilized in a variety of applications such as drug delivery scaffolds and catalyst supports. Functionalization of the surface can be achieved by either grafting of alkoxy silanes or co-condensation of the organosilane with the inorganic silica source. My research in this area can be divided into two components. In the first, we address the significant issue of metal contamination after reactions that are catalyzed by transition metals. In the second, we examine the design of new catalysts based on organic/inorganic composites. Ruthenium catalyzed processes such as olefin metathesis or asymmetric hydrogenation, are often underutilized due to the difficulty of removing the ruthenium by-products. Attempts to remove ruthenium involve treating the solution with a scavenging reagent followed by silica chromatography. Often these scavenging agents are expensive phosphines or toxic agents like lead tetra-acetate. SBA-15 functionalized with aminopropyl triethoxysilane displays a high affinity for ruthenium. Furthermore, it can be utilized to remove ruthenium by-products from olefin metathesis or hydrogenation reactions without the need for silica chromatography. We have also prepared sulfur-functionalized mesoporous silicates that have a high affinity for palladium. The materials after loading prove to be active catalysts for a variety of palladium catalyzed processes such as Suzuki-Miyaura and Sonogashira couplings. The catalysts are recyclable with moderate loss of activity and structure, depending on the method of incorporation of the thiol. We have characterized the as-synthesized and used catalysts by nitrogen sorption, TEM, X-ray photoelectron spectroscopy (XPS) and a variety of homogeneity tests were performed on the catalysts. Periodic mesoporous organosilicates (PMOs) are a well known class of inorganic-organic hybrid materials. The majority of PMOs prepared utilize simple organic bridges such as ethyl, phenyl or biphenyl. The use of a chiral organic bridging group, such as BINAP, allows the synthesis of chiral PMOs with possible applications in catalysis and separation science. The synthesis of a triethoxysilyl functionalized BINAP as well as its incorporation into PMO materials with 4,4’-bistriethoxysilyl biphenyl or tetraethylorthosilicate as co-silica sources are described.en
dc.format.extent14165145 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectMaterials Chemistryen
dc.subjectMesoporous Silicaen
dc.subjectSupported Catalysisen
dc.subjectHeterogeneity Testsen
dc.subjectChiral Periodic Mesoporous Silicaen
dc.titleOrganically Modified Mesoporous Silica as a Support for Synthesis and Catalysisen
dc.typethesisen
dc.description.degreePhDen
dc.contributor.supervisorCrudden, Cathleen M.en
dc.contributor.departmentChemistryen
dc.degree.grantorQueen's University at Kingstonen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record