title: A general strategy for the rational design of size-selective mesoporous catalysts.
abstract: A series of functionalized mesoporous silicas with cagelike pore topology has been synthesized and screened for size-selective catalytic transformations. The aluminum-catalyzed Meerwein-Ponndorf-Verley (MPV) reduction of differently sized aromatic aldehydes (benzaldehyde and 1-pyrenecarbox-aldehyde) has been investigated as a test reaction. The catalysts were synthesized in a two-step grafting sequence comprising pore-size engineering of mesoporous silicas (SBA-1, SBA-2, SBA-16) with long-chain alkyl dimethylaminosilanes and surface organoaluminum chemistry with triethylaluminum [{Al(CH(2)CH(3))3}2]. Size-selective reaction behavior was found for small pore SBA-1 materials, and the selectivity could be efficiently tuned by selecting a silylating reagent of appropriate size. The results are compared with the catalytic performance of a large-pore periodic mesoporous organosilica PMO[SBA-1] and the nonporous high-surface-area silicas Aerosil 300/380.
authors.affiliation: Kjemisk Institutt, Universitetet i Bergen, Allégaten 41, 5007 Bergen, Norway.
authors.forename: Clemens
authors.initials: C
authors.lastname: Zapilko
authors.forename: Yucang
authors.initials: Y
authors.lastname: Liang
authors.forename: Willy
authors.initials: W
authors.lastname: Nerdal
authors.forename: Reiner
authors.initials: R
authors.lastname: Anwander