Synthesis of superacid-functionalized mesoporous nanocages with tunable pore diameters and their application in the synthesis of coumarins

Kalita, Pranjal, Sathyaseelan, B., Mano, Ajayan, Zaidi, S. M. Javaid, Chari, Murugulla A. and Vinu, Ajayan (2010) Synthesis of superacid-functionalized mesoporous nanocages with tunable pore diameters and their application in the synthesis of coumarins. Chemistry: A European Journal, 16 9: 2843-2851. doi:10.1002/chem.200902531


Author Kalita, Pranjal
Sathyaseelan, B.
Mano, Ajayan
Zaidi, S. M. Javaid
Chari, Murugulla A.
Vinu, Ajayan
Title Synthesis of superacid-functionalized mesoporous nanocages with tunable pore diameters and their application in the synthesis of coumarins
Journal name Chemistry: A European Journal   Check publisher's open access policy
ISSN 0947-6539
1521-3765
Publication date 2010-03-01
Sub-type Article (original research)
DOI 10.1002/chem.200902531
Volume 16
Issue 9
Start page 2843
End page 2851
Total pages 9
Place of publication Weinheim, Germany
Publisher Wiley
Language eng
Formatted abstract
Here we demonstrate for the first time the preparation of a triflic acid (TFA)-functionalized mesoporous nanocage with tunable pore diameters by the wet impregnation method. The obtained materials have been unambiguously characterized by XRD, N2 adsorption, FTIR spectroscopy, and NH3 temperature-programmed desorption (TPD). From the characterization results, it has been found that the TFA molecules are firmly anchored on the surface of the mesoporous supports without affecting their acidity. We also demonstrate the effect of the pore and cage diameter of the KIT-5 supports on the loading of TFA molecules inside the pore channels. It has been found that the total acidity of the materials increases with an increase in the TFA loading on the support, whereas the acidity of the materials decreases with an increase in the pore diameter of the support. The acidity of the TFA-functionalized mesoporous nanocages is much higher than that of the zeolites and metal-substituted mesoporous acidic catalysts. The TFA-functionalized materials have also been employed as the catalysts for the synthesis of 7-hydroxy-4-methylcoumarin by means of the Pechmann reaction under solvent-free conditions. It has been found that the catalytic activity of the TFA-functionalized KIT-5 is much higher than that of zeolites and metal-substituted mesoporous catalytic materials in the synthesis of coumarin derivatives. The stability of the catalyst is extremely good and can be reused several times without much loss of activity in the above reaction.
Keyword Heterogeneous catalysis
Mesoporous materials
Nanostructures
Pechmann reaction
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Australian Institute for Bioengineering and Nanotechnology Publications
 
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