Cobalt nanoparticles in hollow mesoporous spheres as a highly efficient and rapid magnetically separable catalyst for selective epoxidation of styrene with molecular oxygen

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Cobalt nanoparticles in hollow mesoporous spheres as a highly efficient and rapid magnetically separable catalyst for selective epoxidation of styrene with molecular oxygen

Zhi-Qiang Shi,^ab   Li-Xin Jiao,^ab   Jian Sun,^ab   Zi-Bao Chen,^a  Yuan-Zhe Chen,^ab   Xiao-Hang Zhu,^ab   Jing-Hui Zhou,^ab  Xin-Chun Zhou,^ab   Xin-Zhe Li^ab and   Rong Li*^ab  

*

Corresponding authors

^a

State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, China 
E-mail: liyirong@lzu.edu.cn
Fax: +86 0931 891 2582 
Tel: +86 0931 891 2311

^b

The Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering Lanzhou University, Lanzhou 730000, China

RSC Adv., 2014,4, 47-53

DOI: 10.1039/C3RA45383A

 http://pubs.rsc.org/en/content/articlelanding/2014/ra/c3ra45383a/unauth#!divAbstract

Uniform rattle-type hollow mesoporous spheres (HMS) with large cavities have been successfully prepared by the colloidal carbon spheres as templates. The spheres are well monodispersed and nearly uniform in dimension with particle size of ca. 150 nm. Co nanoparticles composed of HMS were found to be a highly efficient catalyst for selective epoxidation of styrene under mild reaction conditions. The catalysts can be easily separated from the reaction mixtures by an external magnet, and reused five times without significant loss of catalytic activity.

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 STYRENE OXIDE



 













 EXTRAS FROM NET
Chiral GC
Column: Supelco (#24301): -DEX 110 30 m capillary column
Carrier Gas: Helium
Pressure: 22 psi
Split Ratio: 50:1
Detector: Flame Ionization Detector (FID)
Styrene Oxide Analysis:
Oven Temperature: 100 °C
Retention times of the two enantiomers: 10.3 and 10.6 min
Typical percentages of the two enantiomers using catalyst synthesized using L-Tartaric acid: 92.7% (10.3 min RT), 7.3% (10.6 min RT)
Typical percentages of the two enantiomers using catalyst synthesized using D-Tartaric acid: 2.7% (10.3 min RT), 97.2% (10.6 min RT)
1-Phenyl-1,2-ethanediol Acetonide Analysis:
Oven Temperature: 130 °C
Retention time of the two enantiomers: 9.6 and 9.9 min
Typical percentages of the two enantiomers using catalyst synthesized using L-Tartaric acid: 4.7% (9.6 min RT), 95.3% (9.9 min RT)
Typical percentages of the two enantiomers using catalyst synthesized using D-Tartaric acid: 96.0% (9.6 min RT), 4.0% (9.9 min RT)
Optical Rotation
Jacobsen reports that the R enantiomer of styrene oxide is the major one remaining using the (R,R) catalyst. (This is the catalyst produced using the L-Tartaric acid.) For a sample with >99% ee he reports: []²³_D +28.6° (neat).
Jacobsen reports that the S enantiomer of the diol is the major one produced using the (R,R) catalyst. (This is the catalyst produced using the L-Tartaric acid.) For a sample with 95% ee he reports: []²³_D +38.4° (c 4.38, EtOH).






tirupati, india
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Tirupati తిరుపతి
City
Clockwise from top: Tirumala Venkateswara Temple, Tirumala ghat road, City skyline and Chandragiri fort
Tirupati Location in Andhra Pradesh, India
Coordinates: 13.65°N 79.42°ECoordinates: 13.65°N 79.42°E
Country	India
State	Andhra Pradesh
Region	Rayalaseema
District	Chittoor
Government
• Member of Parliament	Varaprasad Rao Velagapalli
Area
• City	24 km2 (9 sq mi)
Elevation	161 m (528 ft)
Population (2011)[1]
• City	287,035
• Density	12,000/km2 (31,000/sq mi)
• Metro[2]	459,985
Languages
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Time zone	IST (UTC+5:30)
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Vehicle registration	AP 03
Website	Tirupati Mucnicipal Corporation

 




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