Jozef Hodyl PhD Thesis - Theses - Flinders University

Chemical modification of the silica surface with GPTS, 32, was accomplishedby treating dried chromatographic silica gel, 70 - 230 mesh, with an excess ofracemic 3-(glycidoxypropyl)trimethoxysilane (GPTS), 32, stirred in dry toluene at90 ° C for 24 hours, Scheme 4.1.32GPTS33Si-GPSScheme 4.1 Silanisation of silica surface with potentially cross-linking silane coupling agent, GPTS,32.After filtration and washing with MeOH and toluene the silanised silica material wassubjected to Soxhlet extraction in dry toluene for six hours to remove superfluousGPTS. The material was then dried in vacuo for two days and stored in a desiccator.The preparation of the silanised products, Si-GPS 230-400 , 80, and MCM-41-GPS, 81,was performed in the same way.A similar silica material Si-GPDMS, 83, was also prepared by the previouslydescribed silanisation method for Si-GPS, 33, Scheme 4.2.82GPDMES83Si-GPDMSScheme 4.2 Silanisation of silica surface with non-cross-linking silane coupling agent, GPDMES,82.The alkoxysilane linker reactant GPTS, 32, was replaced by racemic 3-72