Raman spectroscopy of supported chromium oxide catalysts. Determination of chromium—oxygen bond distances and bond orders
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چکیده
منابع مشابه
Determination of Molybdenum - Oxygen Bond Distances and Bond Orders by Raman Spectroscopy
A correlation is developed for relating Rarnan stretching frequencies of molybdenum-oxygen ( M 4 ) bonds to their respective bond distances in molybdenum oxide compounds. M+O bond orders are also related to Stretching frequencies. The M 4 correlation is expected to offer invaluable insight into the structures of rnolybdate species in chemical systems which are not amenable to analysis by difkac...
متن کاملDetermination of niobium-oxygen bond distances and bond orders by Raman spectroscopy
An empirical correlation is established for relating Raman stretching frequencies of niobium-oxygen (Nb-O) bonds to their respective bond distances in niobium oxide compounds. The correlation is an exponential least-squares fit between measured Raman frequencies and reported crystallographic bond lengths. Niobium-oxygen bond strengths (in valence units) are also related to Raman stretching freq...
متن کاملIn Situ Raman Spectroscopy of Supported Chromium Oxide Catalysts: O2-O2 Isotopic Labeling Studies
The isothermal isotopic exchange reaction of O2 with 16O of chromium(VI) oxide supported on zirconia, alumina, and titania has been investigated with in situ laser Raman spectroscopy. The isotopic exchange reaction is dependent on the support type, the Cr loading, and the reaction temperature. Complete isotopic exchange of chromium(VI) oxide with O2 is difficult to achieve and requires several ...
متن کاملSitu Raman Spectroscopy of Alumina - Supported Metal Oxide Catalysts
The molecular structures of the surface overlayers of rhenium(VI1) oxide, molybdenum(V1) oxide, tungsten(V1) oxide, chromium(V1) oxide, vanadium(V) oxide, niobium(V) oxide, and titanium( IV) oxide on y-alumina were determined by in situ Raman spectroscopy under dehydrated conditions. It was found that the dehydrated surface metal oxide structures of all the systems under study, except for suppo...
متن کاملDisulfide bond dihedral angles from Raman spectroscopy.
Raman spectra of several compounds containing the CS-SC moiety were obtained (in the solid phase) from 450-800 cm(-1) to investigate the S-S and C-S stretching behavior. The S-S stretching frequency varied linearly with the CS-SC dihedral angle (obtained from either x-ray or neutron diffraction or ultraviolet absorption) for compounds whose CC-SS dihedral angles were not very different. The rat...
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ژورنال
عنوان ژورنال: J. Chem. Soc., Faraday Trans.
سال: 1996
ISSN: 0956-5000,1364-5455
DOI: 10.1039/ft9969201969