Jozef Hodyl PhD Thesis - Theses - Flinders University

7.11 Preparation of the silica materialsSi-(GPS), 33OOOSiOOSilica Surface33To a stirred suspension of silica gel (2.2 g; Merck 70-230 mesh; preheated at120 o C, at, 0.75 mm Hg for 24 h) in dry toluene (50 cm 3 ), 3-(glycidoxypropyl)trimethoxysilane, 32 (2.08 g, 8.8 mmol) was added. The mixturewas stirred at 90 o C for 24 h, cooled to room temperature, filtered and washed withdry toluene (100 cm 3 ) and absolute methanol (100 cm 3 ). The resulting white powder,33, was then subjected to Soxhlet extraction with dry toluene (80 cm 3 ) for 6 h, airdried and stored under vacuum. Microanalysis gave 7.64% C and 1.43% Hcorresponding to a loading of 1.1 mmol g -1 material. IR (KBr, DRIFT): ν (C-H) 2944cm -1 , 2879 cm -1 ; asym. ν (Si-O-Si) 1192cm -1 , 1072 cm -1 ; sym. ν (Si-O-Si) 950 cm -1 , 807 cm -1 .Si-GPS(230-400), 80The preparation of this material was analogous to, 33, using silica gel (1.0 g,Merck 60 230-400 mesh) and 3-(glycidoxypropyl)trimethoxysilane, 32 (950 mg, 4.0mmol). Microanalysis gave 6.34% C and 1.36% H corresponding to a loading of0.88 mmol g -1 of material.147