12-Tungstophosphoric acid (PW) immobilized on carbon-coated Fe3O4 nanoparticles (Fe3O4@C-PW) was prepared through a combination of hydrothermal and chemical co-precipitation. The intermediate carbon layer, which was produced from starch as a green material, protects the magnetic core and also improves the dispersion and catalytic activity of the nanoparticles. Characterization of this catalyst was investigated by high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry, and the acidic properties were studied by NH3-temperature programmed desorption and potentiometric titration. The HRTEM image showed that the catalyst had a well-defined core–shell structure with an average particle size of 50 nm. The characterization data derived from FT-IR reveal that basic structure and geometry of the Keggin anion are preserved after synthesis of Fe3O4@C-PW. The as-prepared Fe3O4@C-PW was used as a nanocatalyst for the synthesis of various bis(indolyl)methanes and β-functionalized indoles in water. The catalyst can be recovered simply using an external magnetic field and reused several times without appreciable loss of its catalytic activity.
Research on Chemical Intermediates – Springer Journals
Published: Aug 27, 2015
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud