Facile and Rational Route for High-Yield Synthesis of Titanasiloxanes from Aminosilanetriols

Reactions of aminosilanetriols RN(SiMe 3 )(Si(OH) 3 ) (R = 2,6-Me 2 C 6 H 3 ( 1a ), 2,6- i -Pr 2 C 6 H 3 ( 1b ), 2,4,6-Me 3 C 6 H 2 ( 1c )) with titanium orthoesters Ti(OR‘) 4 (R‘ = Et, i -Pr) in hexane at room temperature afford new cubic titanasiloxanes [RN(SiMe 3 )SiO 3 Ti(OR‘)] 4 ( 2a − f ) in nearly quantitative yield. These compounds have been characterized by mass, IR, and multinuclear NMR spectroscopy. The X-ray crystal structure of [(2,6- i -Pr 2 C 6 H 3 )N(SiMe 3 )SiO 3 Ti(OEt)] 4 ( 2c ) is described. The molecular structure of 2c reveals a Si 4 Ti 4 O 12 cubic core. The six Si−O−Ti puckered eight-membered rings in the cubic framework adopt a crown conformation with the two Si and two Ti atoms describing a plane and the four oxygen atoms in an almost parallel plane.