Cascade cocondensation of trifunctional chloro- and alkoxysilanes RSiX3 in nonaqueous media

The hydrolytic copolycondensation (HPC) of trifunctional monomers RSiX3 (R = Ph, Me; X are hydrolyzable RO or Cl groups) in nonaqueous organic solvents (toluene, dioxane) was studied. The in situ generation of water necessary for hydrolysis occurred via the reaction of carbamide with acetone or acetylacetone. The cascade synthesis of silsesquioxanes was carried out under the conditions of in situ water generation in nonaqueous media with the quantitative yield of organochloro- and alkoxysilanes from the reaction mixtures. The influence of the conditions of cascade HPC on the compositions, structures, and molecular weight characteristics of the obtained products was studied by GPC, 1H and 29Si NMR, and GC coupled with mass spectrometry.