Roope Astala and Scott M. Auerbach,
``The Properties of Methylene- and Amine-Substituted
Zeolites from First Principles,''
J. Am. Chem. Soc. 126, 1843-1848 (2004).
Abstract
All-silica zeolite frameworks doped with methylene and amine
groups are studied using density functional theory-based
electron structure calculations. Strain energies are calculated
in a novel way, by comparing zeolite energies with appropriate
polymer reference systems. The modified zeolites are found to be
mechanically stable structures with surprisingly little strain.
Distortions due to impurities result in
broadened Si-O-Si angle distributions in the
lattice surrounding defects. Our results suggest that
zeolites can accommodate both methylene and
amine groups at high concentrations with minimal strain.
The amine-doped zeolites are strong Lewis bases
suggesting novel applications in base catalysis.
Prof SM Auerbach
19 March 2004