Abstract
Several novel aluminum alkoxydisilanolate complexes were prepared by
reaction of triphenylsilanol with aluminum 2-methoxyethoxide, aluminum
2-ethoxyethoxide, aluminum sec-butoxide and aluminum iso-propoxide. All
new complexes, (Ph(3)SiO)(2)Al(OR)(2) where R = CH(2)CH(2)OCH(3)
(1), CH(2)CH(2)OC(2)H(5) (2), CH(CH(3))CH(2)CH(3) (3) and CH(CH(3))(2)
(4) were characterized by elemental analysis, mass spectrometry and
infrared spectroscopy (IR), as well as (1)H, (13)C, (29)Si and (27)Al
NMR spectroscopies. The solid-state structures of the representative
compound 2 and 4 were also verified by single-crystal X-ray analyses.
Complexes 2 and 4 are dimers having distorted trigonal bipyramidal and
tetrahedral coordination at the aluminum center, respectively. The
(27)Al NMR spectrum of compound 2 showed that the solid-state structure
of the complex was not retained in solution, and tetracoordinated
aluminum was found in solution in contrast to the pentacoordinated
geometry in the solid state. The hydrothermal treatment of 1 and 4 at
200 degrees C and the subsequent calcination at 1000 degrees C resulted
in the formation of alumina-silica composite (4SiO(2)center dot
Al(2)O(3)) with gamma-alumina in the silica matrix. Copyright (C) 2010
John Wiley & Sons, Ltd.
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