ISSN:
0268-2605
Keywords:
Nickel-σ-organyl complexes
;
dispersed atomic Ni(0)
;
Ni(I) ions
;
silica
;
EPR
;
FMR
;
spectrum calculation
;
strain
;
Chemistry
;
Industrial Chemistry and Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Dispersed atomic nickel(0) is formed during the reaction of the nickel-σ-organyl complexes with silanol groups at temperatures below 373 K. That nickel is oxidized to Ni(I) by protons of the silanol groups in a consecutive step. The Ni(I) portion amounts to about 70% w/w of the Ni used. Six different Ni(I) species are detected by electron paramagnetic resonance. They are stabilized by interaction with the silica surface and the organic moieties; they act as anchor ions for the Ni(0) atoms. Ni(0) crystallites stabilized in this way are about 0.5 nm in diameter after a treatment at 373 K. The influence of the Ni(I) ions on the collective, magnetic properties of the clusters is revealed by calculation of ferromagnetic resonance (FMR) spectra using the independent-grain approach according to Schlömann and Kotyukov. A strain of about 10 GPa is brought about in the nickel crystallites by the interaction with Ni(I) ions. © 1998 John Wiley & Sons, Ltd.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource