Reactions of Group IV Metallocene Dichlorides with Modified Silica Gel Surfaces

Effect of Particle Structure and Surface Chemistry on PMMA Adsorption to Silica Nanoparticles

“…The "as-received" SiO 2 was thermally modified by heat treatment at 600 and 1000 °C for 6 h. Thermally treated samples were further acid treated using 1 M sulfuric acid (H 2 SO 4 ) solution for 24 h, and rinsed with distilled water until a pH of 7.0 was achieved. The SiO 2 heated to 1000 °C was made hydrophobic by chemical modification with hexamethyl disilazane (HMDS), which reacts with isolated silanol groups 38 and covers the surface with trimethylsilyl groups (-Si-(CH 3 ) 3 ) (TMS); HMDS is also used in the commercial process to silanate Aerosil R812. Samples were stored in a desiccator until further use.…”

Modified silicas as supports for single-site zirconocene catalysts

“…8 ). Blitz and coworkers [22] reported a similar reaction between 1 and a fully-silylated silica. In this case, the reaction between the metallocene and the modified silica surface was performed at room temperature for only 2 h. A small amount (0.03% Zr) of metallocene was then grafted in a similar way to our experiment.…”

Supported (nBuCp)2ZrCl2 Catalysts: Effects of Selected Lewis Acid Organotin Silica Surface Modifiers on Ethylene Polymerization

“…the relevant literature cited therein, and ref 15–18. and39–44. Also note that the coordination number and geometry about Sn in n Bu(OH) 2 SnCl, MeSnCl 3 , and n BuSnCl 3 differ with the ligand types 58–65.…”

“…Scheme illustrates how this inactive species could form in absence of functionalization of silica by the organotin compounds and subsequent loading of MAO. The literature shows that, when a partially dehydroxylated silica is contacted with a organochloro compound, the reaction particularly occurs between the Brönsted (≡SiOH) isolated silanol group and the Cl ligand, producing HCl10, 15–18, 39–44. Scheme has been designed accordingly.…”