Accession Number : ADA183824

Title :   Catalytic Synthesis of Oligosilazanes. 2,

Corporate Author : SRI INTERNATIONAL MENLO PARK CA

Personal Author(s) : Biran,Claude ; Blum,Yigal D ; Laine,Richard M ; Glaser,Robert ; Tse,Doris S

PDF Url : ADA183824

Report Date : 23 Jul 1987

Pagination or Media Count : 14

Abstract : Preliminary studies on transition metal catalyzed dehydrocoupling of Silicon hydrogen bonds with Hydrogen nitrogen bonds to form silicon nitrogen bonds, silazanes, and hydrogen are described. A number of transition metal complexes have been tested as catalyst precursors for the dehydrocoupling reaction. Of these, Ru2(CO)8(Et3Si)2 proved to be the most active homogeneous catalyst and Palladium particles produced by the in situ reduction of Pd(OAc)2 were the most active heterogeneous catalysts. The kinetics studies of the ruthenium catalyzed reaction of Et3SiH with primary amines, RNH2 were run at 70C in THF. The effects of changes in Et3SiH amine and catalyst concentrations on rates of reaction were examined. The data suggest that catalysis involves an extremely complex set of reaction were examined. The data suggest that catalysis involves an extremely complex wet of equilibria wherein the rate determining step is dependent on the steric requirements of the amine and fragmentation of the starting Ru3(CO)12 cluster. Keywords: Polysilazanes; Preceramic ploymers; Silicon hydrogen bond activation catalysis; Kinetic and mechanistic studies.

Descriptors :   *CATALYSTS, *POLYMERS, *SILICON COMPOUNDS, *SYNTHESIS(CHEMISTRY), AMINES, CATALYSIS, CATALYSTS, CONCENTRATION(COMPOSITION), FRAGMENTATION, HYDROGEN, HYDROGEN BONDS, METAL COMPLEXES, NITROGEN, PALLADIUM, PARTICLES, PRECURSORS, RUTHENIUM, SILICON, TRANSITION METALS, DECOUPLING(INTERACTION), SILICON CARBIDES, COUPLING(INTERACTION), REACTION KINETICS, SILICON NITRIDES

Subject Categories : Polymer Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE