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Synthesis, characterization and single crystal structure determination of aluminum alkoxydisilanolates: precursors for silica–alumina composite
Author(s) -
Amini Mostafa M.,
Mohammadnezhad Gholamhossein,
Mirzaee Mehdi,
Khavasi Hamid Reza
Publication year - 2010
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1634
Subject(s) - chemistry , aluminium , calcination , infrared spectroscopy , trigonal bipyramidal molecular geometry , crystal structure , single crystal , crystallography , solid state nuclear magnetic resonance , nuclear magnetic resonance spectroscopy , hydrothermal synthesis , inorganic chemistry , stereochemistry , hydrothermal circulation , organic chemistry , catalysis , chemical engineering , nuclear magnetic resonance , physics , engineering
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 °C and the subsequent calcination at 1000 °C resulted in the formation of alumina–silica composite (4SiO 2 ·Al 2 O 3 ) with γ‐alumina in the silica matrix. Copyright © 2010 John Wiley & Sons, Ltd.