Discrete Complexes Immobilized onto Click-SBA-15 Silica: Controllable Loadings and the Impact of Surface Coverage on Catalysis

被引:105
作者
Nakazawa, Jun [1 ]
Smith, Brian J. [1 ]
Stack, T. Daniel P. [1 ]
机构
[1] Stanford Univ, Dept Chem, Stanford, CA 94305 USA
关键词
SBA-15 MESOPOROUS SILICA; ASYMMETRIC EPOXIDATION; CLICK-CHEMISTRY; SITE-ISOLATION; ALKENE EPOXIDATION; POROUS SILICA; AMINE GROUPS; REACTIVITY; OLEFINS; FUNCTIONALIZATION;
D O I
10.1021/ja210400u
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Azidopropyl functionalized mesoporous silica SBA-15 were prepared with variable azide loadings of 0.03-0.7 mmol g(-1) (similar to 2-50% of maximal surface coverage) through a direct synthesis, co-condensation approach. These materials are functionalized selectively with ethynylated organic moieties through a copper-catalyzed azide alkyne cycloaddition (CuAAC) or "click" reaction. Specific loading within a material can be regulated by either the azide loading or limiting the alkyne reagent relative to the azide loading. The immobilization of ferrocene, pyrene, tris(pyridylmethyl)amine (TPA), and iron porphyrin (FeTPP) demonstrates the robust nature and reproducibility of this two-step synthetic attachment strategy. Loading-sensitive pyrene fluorescence correlates with a theoretically random surface distribution, rather than a uniform one; site-isolation of tethered moieties similar to 15 angstrom in length occurs at loadings less than 0.02 mmol g(-1). The effect of surface loading on reactivity is observed in the oxygenation of SBA-15-[Cu-I(TPA)]. SBA-15-[Mn-II(TPA)]catalyzed epoxidation exhibits a systematic dependence on surface loading. A comparison of homogeneous, site-isolated and site-dense complexes provides insight into catalyst speciation and ligand activity.
引用
收藏
页码:2750 / 2759
页数:10
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共 70 条
[21]   "Click" tetradentate ligands [J].
Hao, Erhong ;
Wang, Zhaoyun ;
Jiao, Lijuan ;
Wang, Shaowu .
DALTON TRANSACTIONS, 2010, 39 (10) :2660-2666
[22]   Assessing site-isolation of amine groups on aminopropyl-functionalized SBA-15 silica materials via spectroscopic and reactivity probes [J].
Hicks, Jason C. ;
Dabestani, Reza ;
Buchanan, A. C., III ;
Jones, Christopher W. .
INORGANICA CHIMICA ACTA, 2008, 361 (11) :3024-3032
[23]   Spacing and site isolation of amine groups in 3-aminopropyl-grafted silica materials: The role of protecting groups [J].
Hicks, Jason C. ;
Dabestani, Reza ;
Buchanan, A. C., III ;
Jones, Christopher W. .
CHEMISTRY OF MATERIALS, 2006, 18 (21) :5022-5032
[24]   Silica-based mesoporous organic-inorganic hybrid materials [J].
Hoffmann, Frank ;
Cornelius, Maximilian ;
Morell, Jurgen ;
Froeba, Michael .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2006, 45 (20) :3216-3251
[25]   "Click" Grafting of High Loading of Polymers and Monosaccharides on Surface of Ordered Mesoporous Silica [J].
Huang, Liang ;
Dolai, Sukanta ;
Raja, Krishnaswami ;
Kruk, Michal .
LANGMUIR, 2010, 26 (04) :2688-2693
[26]   Biomimetic aryl hydroxylation derived from alkyl hydroperoxide at a nonheme iron center.: Evidence for an FeIV=O oxidant [J].
Jensen, MP ;
Lange, SJ ;
Mehn, MP ;
Que, EL ;
Que, L .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2003, 125 (08) :2113-2128
[27]   Clicking Fluoroionophores onto Mesoporous Silicas: A Universal Strategy toward Efficient Fluorescent Surface Sensors for Metal Ions [J].
Jin, Zhen ;
Zhang, Xiao-Bing ;
Xie, De-Xun ;
Gong, Yi-Jun ;
Zhang, Jing ;
Chen, Xin ;
Shen, Guo-Li ;
Yu, Ru-Qin .
ANALYTICAL CHEMISTRY, 2010, 82 (15) :6343-6346
[28]   Synthesis and characterization of poly-L-lysine grafted SBA-15 using NCA polymerization and click chemistry [J].
Kar, Mrityunjoy ;
Malvi, Bharmana ;
Das, Anindita ;
Panneri, Suyana ;
Sen Gupta, Sayam .
JOURNAL OF MATERIALS CHEMISTRY, 2011, 21 (18) :6690-6697
[29]   Hybrid inorganic-organic mesoporous materials [J].
Kickelbick, G .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2004, 43 (24) :3102-3104
[30]   BOUND PYRENE EXCIMER PHOTOPHYSICS AND THE ORGANIZATION AND DISTRIBUTION OF REACTION SITES ON SILICA [J].
LOCHMULLER, CH ;
COLBORN, AS ;
HUNNICUTT, ML ;
HARRIS, JM .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1984, 106 (15) :4077-4082