3788
Y. Chen et al. / Journal of Organometallic Chemistry 690 (2005) 3783–3789
0.8
Powder X-ray diffraction (XRD) patterns were recorded
with a Bruker D4 powder X-ray diffractometer using Cu
Ka radiation. Elemental analyses were carried out on a
Rapid CHN–O analyzer and a S4 EXPLORER X-ray
Spectrometer. Gas–liquid chromatograms were per-
formed on a HP 6890 series chromatograph equipped
with a FID detector and a HP 5793 mass-spectrometer
detector using He as a carrier gas.
600
550
500
450
400
350
300
250
200
150
100
50
S1
S2
S3
0.6
0.4
0.2
0.0
0
2
4
6
8
10
12
14
16
Pore Diameter(nm)
4.2. Immobilization of Sm[N(SiMe3)2]3 onto SBA-15
Tris[bis(trimethylsilyl)amido]samarium (0.52 g) was
dissolved in n-hexane (10 ml), and was quickly added
to a suspension of the dehydrated SBA-15 (0.78 g) in
n-hexane (10 ml). After stirring at ambient temperature
for 72 h, the reaction mixture was centrifuged and the
solution was decanted. The precipitate was washed sev-
eral times with n-hexane (20 ml) and dried in vacuum for
3 h to give S2 as a pale-yellow powder. Removal of sol-
vent from the solution left 0.04 g unreacted silylamide.
0
0.0
0.2
0.4
0.6
0.8
1.0
Relative Pressure(P/P0)
Fig. 3. N2 adsorption–desorption isotherms at 77 K and pore size
distribution profiles of SBA-15 (S1), hybrid material (S2) and
recovered material (S3).
was filtered through the MgSO4 pad. The resulting dry
organic layer was then analyzed by GLC.
S1: White powder, BET surface area: 463.7 m2/g.
BJH pore diameter: 7.74 nm. IR (KBr): m = 3442 (s),
4.3.2. Condensation reactions of aldehydes catalyzed by
the hybrid material
162s9 (m), 1080 (s), 804 (s) cmÀ1
.
S2: Pale yellow powder, BET surface area: 273.4
m2/g. BJH pore diameter: 6.96 nm. Anal. Found: C,
13.21; H, 3.72; N, 1.96; Sm, 16.1%. IR (KBr):
m = 3417 (m), 2964 (m), 1627 (m), 1525 (m), 1392
The hybrid material (2.5 mol% metal) suspended in n-
hexane (2 ml) was stirred in a reaction flask. The sub-
strate (0.1 g) dissolved in toluene (2 ml) was added to
the catalyst. After stirring for 24 h, the catalyst was sep-
arated from the reaction mixture by centrifugation and
washed several times with hexane. The combined organic
layer was analyzed by GLC. The recovered material was
dried in vacuum and reused for the next run.
(m), 1080 (s), 846 (s), 806 (s) cmÀ1
.
S3:Yellow powder, BET surface area: 270.9 m2/g.
BJH pore diameter: 6.65 nm. Anal. Found: C,
16.29; H, 1.62; N, 0.48; Sm, 14.6%. IR (KBr):
m = 3411 (m), 2964 (m), 2921 (m), 2852 (m), 1594
(m), 1542 (m), 1421 (m), 1087 (s), 804 (m) cmÀ1
.
4.3.3. Mixed Tishchenko reaction
A mixture of two different aldehydes in 1:1 molar ra-
tio were dissolved in toluene (2 ml) and added to the cat-
alyst in n-hexane (2 ml) under the protection of N2.
After the reaction was completed, the mixture was
quenched, extracted and analyzed as described above
(see Fig. 3).
4.3. General catalytic procedure
The catalytic reactions were carried out under the
protection of nitrogen. The qualitative and quantitative
analysis of the reactants and the products was made by
GLC. Yields were determined by GLC based on the rel-
ative area of GLC signals referred to the internal stan-
dard (n-dodecane). Selectivity is represented by
product distribution based on the relative area of GLC
signals. Standard lipid products were prepared by the
literature procedures [7].
Acknowledgments
We thank the National Natural Science Foundation
of China and the Research Fund for the Doctoral Pro-
gram of Higher Education of China and the New Cen-
tury Distinguished Scientist of National Education
Ministry of China for financial support.
4.3.1. Condensation reactions of aldehydes catalyzed by
Sm[N(SiMe3)2]3
The catalyst (2.5 mol% metal) dissolved in n-hexane
(2 ml) was stirred in a reaction flask. The substrate
(0.1 g) dissolved in toluene (2 ml) was directly added
to the catalyst. After stirring for 24 h, the reaction mix-
ture was quenched with 2 ml of water, and extracted
with CH2Cl2 (3 · 2 ml). The combined organic extract
References
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[2] R. Anwander, O. Runte, J. Eppinger, J. Chem. Soc., Dalton
Trans. (1997) 137.