18157-20-5Relevant articles and documents
Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes
Sugiyama, Tomoaki,Shiba, Hiroya,Yoshikawa, Masashi,Wada, Hiroaki,Shimojima, Atsushi,Kuroda, Kazuyuki
, p. 2764 - 2772 (2019/02/01)
The controlled synthesis of oligosiloxanes with well-defined structures is important for the bottom-up design of siloxane-based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra- and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy- and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So-called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe2Vi (Vi=vinyl). These findings will enable the creation of siloxane-based materials with diverse functions.
Effect of substituents on the silicon atom on etherification of organochlorosilanes with ethanol
Chernyshev,Belyakova,Komarov,Bykovchenko
, p. 1038 - 1040 (2007/10/03)
The kinetics of etherification of organochlorosilanes with various substituents on the silicon atom with ethanol were studied. The etherification rate is mostly controlled by the inductive constants of the substituents and increases as the electron-acceptor power of the substituents increases. The ρ* value in the Taft equation for etherification of organochlorosilanes with ethanol was determined.
ETHERIFICATION OF METHYLTRICHLOROSILANE WITH ALIPHATIC ALCOHOLS.
Utkin,Pavlova,Kolobkov,Vasil'ev
, p. 601 - 605 (2007/10/02)
The authors report the results of a study of etherification of MTCS with C//2-C//4 aliphatic alcohols. It is shown experimentally that the rate of etherification of MTCS falls with increase of the molecular weight of the aliphatic alcohol. Etherification is slower with alcohols of branched structure than with the corresponding alcohols of normal structure. The rate of etherification of MTCS decreases with decrease of the number of chlorine atoms in the organochlorosilane molecule, and the final stage is reversible.