Cyclohexyl trichlorosilane

For most of the trichlorosilane concentration tested, the order of activity is still cyclopentyl > cyclohexyl > phenyl. At low concentration the order between cyclohexyl and phenyl reverses but cyclopentyl still results in the best activity. This confirms the starting hypothesis that the R group is a more relevant factor than the concentration of the silane in influencing the hydrolytic condensation. The maximum activity corresponds to a different silane concentration for each of the three R groups. The maximum for cyclopentyl as R group - corresponding to a concentration of silane of 0.181 M - displays an activity that is 95% of that of pure Ti-(cyclopentyl silsesquioxane a7b3) this is a relevant improvement compared with the optimum obtained previously (87%) [39]. These results show that the experi-... 

A new parameter space for the synthesis of silsesquioxane precursors was defined by six different trichlorosilanes (R=cyclohexyl, cyclopentyl, phenyl, methyl, ethyl and tert-butyl) and three highly polar solvents [dimethyl sulfoxide (DMSO), water and formamide]. This parameter space was screened as a function of the activity in the epoxidation of 1-octene with tert-butyl hydroperoxide (TBHP) [26] displayed by the catalysts obtained after coordination of Ti(OBu)4 to the silsesquioxane structures. Fig. 9.4 shows the relative activities of the titanium silsesquioxanes together with those of the titanium silsesquioxanes obtained from silsesquioxanes synthesised in acetonitrile. The values are normalised to the activity of the complex obtained by reacting Ti(OBu)4 with the pure cyclopentyl silsesquioxane o7b3 [(c-C5H9)7Si7012Ti0C4H9]. 

---