Periodic Mesoporous Organosilicas Containing Interconnected [Si(CH2)]3 Rings
Kai Landskron,1
Benjamin D. Hatton,1,2
Doug D. Perovic,2
Geoffrey A. Ozin*1
A periodic mesoporous organosilica composed of interconnected
three-ring [Si(CH
2)]
3 units built of three SiO
2(CH
2)
2 tetrahedral
subunits is reported. It represents the archetype of a previously
unknown class of nanocomposite materials in which two bridging
organic groups are bound to each silicon atom. It can be obtained
with powder and oriented film morphologies. The nanocomposite
is self-assembled from the cyclic three-ring silsesquioxane
[(EtO)
2Si(CH
2)]
3 precursor and a surfactant mesophase to give
a well-ordered mesoporous framework. Low dielectric constants
and good mechanical stability of the films were measured, making
this material interesting for microelectronic applications.
Methylene group reactivity of the three-ring precursor provides
entry to a family of nanocomposites, exemplified by the synthesis
and self-assembly of [(EtO)
2Si(CHR)][(EtO)
2Si(CH
2)]
2 (where
R indicates iodine, bromine, or an ethyl group).
2 Department of Materials Science and Engineering, 184 College Street, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
* To whom correspondence should be addressed. E-mail: gozin{at}alchemy.chem.utoronto.ca
