Size-Selective Mesoporous Catalysts
FULL PAPER
(117.0 g, 6.5 mol). The solution was warmed to 358C, TEOS (11.7 g,
56.0 mmol) was added and the resulting mixture was stirred for about
15 min at this temperature. The mixture was treated for 24h under static
conditions at 358C and then heated to 1008C and kept at this tempera-
ture for 24h. The mesoporous silica was recovered by filtration without
washing, dried overnight in air at ambient temperature and then calcined
at 5408C. The molar composition of the synthesis gel was 0.004Pluronic
F127 : 1TEOS : 4HCl : 130H2O.
AlEtx@PMO
[SBA-1] (600 mg) and triethylaluminum (164mg, 1.44mmol) yielded
632 mg of AlEtx@PMO[SBA-1].
A
AHCTREUNG
AlEtx@SiMe2C8H17@SBA-16: SiMe2C8@SBA-16 (125 mg) and triethylalu-
minum (0.69 mg, 0.60 mmol) yielded 136 mg of AlEtx@SiMe2C8H17@
SBA-16.
AlEtx@SiMe2C18H37@SBA-16: SiMe2C18H37@SBA-16 (125) mg and trie-
thylaluminum (69 mg, 0.60 mmol) yielded 128 mg of AlEtx@
SiMe2C18H37@SBA-16.
PMO
A
(4.24 g,
18-3-1
7.59 mmol), NaOH (3.78 g, 94.50 mmol), and warm deionized water
(334g, 18.6 mol) was stirred for 1 h to form a clear solution. Then 1,2-
bis(triethoxysilyl)ethane (BTEE, 14.64 g, 40.05 mmol) was added. Stirring
the resulting solution for 24h at 25 8C and subsequent heating at 958C
for 6 h brought about precipitation. The final suspension was aged at
958C for 24h. The warm precipitate was recovered by suction filtration
without water washing. The molar composition of the synthesis gel was
0.36C18TABr : 0.19C18-3-1 : 40.05BTEE : 2.36NaOH : 464H2O.
AlEtx@SBA-2: SBA-2 (374mg) and triethylaluminum (205 mg,
1.79 mmol) yielded 372 mg of AlEtx@SBA-2.
AlEtx@Aerosil380: Aerosil380 (300 mg) and triethylaluminum (200 mg,
1.76 mmol) yielded 311 mg of AlEtx@Aerosil380.
AlEtx@SiMe2C8H17@Aerosil300: SiMe2C8H17@Aerosil300 (280 mg) and
triethylaluminum (28 mg, 0.24mmol) yielded 294mg of AlEt
SiMe2C8H17@Aerosil300.
@
x
AlEtx@SiMe2C18H37@Aerosil300: SiMe2C18H37@Aerosil300 (250 mg) and
triethylaluminum (28 mg, 0.24mmol) yielded 233 mg of AlEt x@
SiMe2C18H37@Aerosil300.
The surfactant was removed by a two-step procedure. The as-synthesized
mesoporous organosilica (2.0 g) was stirred in ethanol (250 mL) and hy-
drochloric acid (37%, 10 g) solution at 50–608C for 6 h, and afterwards
the solid separated by suction filtration and dried in air. Then the surfac-
tant was further extracted in hydrochloride-acidified ethanol solution for
24h by using the Soxhlet technique. A weight loss of about 35–45% was
found after a complete solvent extraction. Elemental analysis for the de-
MPV reductions
Reactions were conducted at ambient temperature under an argon at-
mosphere in a magnetically stirred flask. The flask was charged with an-
hydrous 2-propanol (4mL), toluene (1.3 mL), benzaldehyde (66 mg,
0.625 mmol), 1-pyrenecarboxaldehyde (144 mg, 0.625 mmol), and the cat-
alyst (the amount of catalyst was adjusted to 6.610À2 mmol Al). Sam-
ples were taken periodically and analysed by GC, with dodecane as inter-
nal standard. Products were identified by NMR spectroscopy.
hydrated solvent-extracted PMO[SBA-1]: C: 16.51, H: 3.39, N: <0.01.
G
Silylated hybrid materials
General procedure for the synthesis of alkyl dimethylsilylated hybrid ma-
terials: In a glovebox, mesoporous silica (SBA-1: 4.01 mmol OH groups
per g, SBA-16: 3.03 mmol OH groups per g, calculated from carbon anal-
ysis of completely dimethylsilylated materials) was suspended in hexane
and a hexane solution of the alkyl dimethyl(dimethylamido)silane (0.30
À
equivalents relative to surface Si OH groups) was added. The mixture
was stirred at ambient temperature overnight, washed several times with
hexane, and dried under vacuum until constant weight.
Acknowledgements
The authors thank the Universitetet
SCIENCE@UiB), the Deutsche Forschungsgemeinschaft, and the Fonds
der Chemischen Industrie for support.
i Bergen (program NANO-
SiMe2C8H17@SBA-1: SBA-1 (157 mg) and dimethyl(dimethylamido)octyl-
silane (40 mg, 0.19 mmol) yielded 168 mg of SiMe2C8H17@SBA-1.
SiMe2C18H37@SBA-1: SBA-1 (250 mg) and dimethyl(dimethylamido)octa-
decylsilane (100 mg, 0.28 mmol) yielded 249 mg of SiMe2C18H37@SBA-1.
SiMe2C8H17@SBA-16: SBA-16 (300 mg) and dimethyl(dimethylamido)oc-
tylsilane (58 mg, 0.27 mmol) yielded 284mg of SiMe 2C8H17@SBA-16.
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Aerosil300.
SiMe2C18H37@Aerosi300: Aerosil300 (300 mg) and dimethyl(dimethyl-
A
SiMe2C18H37@Aerosil300.
Aluminated hybrid materials
General procedure for the synthesis of aluminated hybrid materials: In
an argon-filled glovebox, the mesoporous silica or organosilica, the meso-
porous hybrid material, Aerosil380 or Aerosil300 were suspended in
hexane and excess of triethylaluminum was added. The mixture was stir-
red at ambient temperature overnight, thoroughly washed with hexane to
remove unreacted triethylaluminum, and dried under vacuum until con-
stant weight.
AlEtx@SBA-1: SBA-1 (150 mg) and triethylaluminum (100 mg,
0.88 mmol) yielded 214mg of AlEt x@SBA-1.
AlEtx@SiMe2C8H17@SBA-1: SiMe2C8H17@SBA-1 (150 mg) and triethyl-
A
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SBA-1.
AlEtx@SiMe2C18H37@SBA-1: SiMe2C18H37@SBA-1 (200 mg) and triethyl-
aluminum (100 mg, 0.88 mmol) yielded 195 mg of AlEtx@SiMe2C18H37@
SBA-1.
Chem. Eur. J. 2007, 13, 3169 – 3176
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