1529-27-7Relevant articles and documents
The Identity in Atomic Structure and Performance of Active Sites in Heterogeneous and Homogeneous, Titanium-Silica Epoxidation Catalysts
Thomas, John Meurig,Sankar, Gopinathan,Klunduk, Marek C.,Attfield, Martin P.,Maschmeyer, Thomas,Johnson, Brian F. G.,Bell, Robert G.
, p. 8809 - 8813 (1999)
The nature of the Ti(IV) active site in heterogeneous titano-silica epoxidation catalysts is shown to be same as that of a Ti(IV)-centered site bound to soluble homogeneous silsesquioxane catalysts. A range of techniques, encompassing pre- and near-edge X-ray absorption spectroscopy and molecular dynamics calculations, provides quantitative information pertaining to the four-coordinated site that is tripodally anchored to silica. The catalytic performance of a series of engineered active sites in [(c-C5H9)7Si7O 12TiOXPh3], where X = Si, Ge, or Sn, shows that the order of enhancement is Ge > Sn > Si. This is compared with previously published7 performances of engineered active sites in solid titano-silicate catalysts. The key importance of accessibility to the four-coordinated Ti(IV) site is highlighted here.
THE CHEMICAL BEHAVIOUR OF COBALT-STABILIZED-CARBENES HAVING A TRISUBSTITUTED SILYL OR GERMYL LIGAND. STEREOSPECIFIC FORMATION OF BENZOYLSILANES FROM THE REACTION OF ORGANOSILYL-COBALT TETRACARBONYL DERIVATIVES WITH PHENYLLITHIUM
Cerveau, Genevieve,Colomer, Ernesto,Corriu, Robert J.P.,Young, J. Colin
, p. 31 - 45 (2007/10/02)
We report the chemical behaviour of cobalt-stabilized carbenes, R3M(CO)3CoC(OEt)R', and their parent anions, R3M(CO)3CoC(O-)R', where M = Si or Ge.The anions where M = Si, R' = Ph decompose thermally into the corresponding benzoylsilanes; when the silicon atom is chiral (R3 = MePh-1-Np) optically active R3SiCOPh is obtained with complete retention of configuration.
