Vibrational study on the local structure of post-synthesis and hybrid mesoporous materials: Are there fundamental distinctions?
authors Vaz, PD; Nunes, CD; Vasconcellos-Dias, M; Nolasco, MM; Ribeiro-Claro, PJA; Calhorda, MJ
nationality International
journal CHEMISTRY-A EUROPEAN JOURNAL
author keywords IR spectroscopy; mesoporous materials; organic-inorganic hybrid composites; Raman spectroscopy; sol-gel process
keywords HETEROCYCLIC BRIDGING GROUPS; MCM-41 MOLECULAR-SIEVES; PORE-SIZE; OH GROUPS; SILICA; ORGANOSILICAS; LIGAND; EPOXIDATION; CHEMISTRY; CATALYSIS
abstract Organic-inorganic mesoporous materials of the MCM-41 type are important materials that can be prepared by either post-synthesis or one-pot synthesis procedures. A complete control of the characteristics at a local level is of the utmost importance in view of the applications of such materials. However, there are not many studies relating such features with synthetic approaches. In this work, we prepared samples by post-synthesis derivatization of materials from Si-based MCM-41, with bidentate nitrogen ligands bearing one or two silylated arms, and by one-pot synthesis of organic-inorganic hybrid materials. The bulk properties of the two kinds of materials were comparable. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and Raman spectroscopy were used to investigate the local environment, namely, the number of OH groups and distribution of SiO4 units (large and small ring units). Hydrophilicity correlates with both the type of organic moiety used (mono- or disilylated), as well as with the synthetic procedure. The same vibrational studies showed how the structure in the channels changes as a function of pressure, reflecting the low mechanical stability of the mesoporous materials.
publisher WILEY-V C H VERLAG GMBH
issn 0947-6539
year published 2007
volume 13
issue 28
beginning page 7874
ending page 7882
digital object identifier (doi) 10.1002/chem.200700310
web of science category Chemistry, Multidisciplinary
subject category Chemistry
unique article identifier WOS:000250032300005
  ciceco authors
  impact metrics
journal analysis (jcr 2019):
journal impact factor 4.857
5 year journal impact factor 4.636
category normalized journal impact factor percentile 75.424
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg