Comparison of thionitrosyl and nitrosyl bonding in dicarbonyl(eta/sup 5/-cyclopentadienyl)chromium complexes by gas-phase ultraviolet and x-ray photoelectron spectroscopy
The gas-phase He I/He II UPS and Mg K..cap alpha.. XPS data for the compounds (eta/sup 5/-C/sub 5/H/sub 5/)Cr(CO)/sub 2/NO and (eta/sup 5/-C/sub 5/H/sub 5/)Cr(CO)/sub 2/NS are reported. The first ionization potentials for the two complexes are nearly the same. A short C-O stretching progression in the first ionization band of the nitrosyl compound shows that it is predominantly associated with metal d character and is symmetrically ..pi.. delocalized into the carbonyls. The next two ionizations for both complexes are sensitive to the ..pi.. symmetry interaction with the NO or NS group. These ionizations are slightly destabilized and are sharper for the NS complex relative to the NO complex, showing stronger metal ..pi.. interaction with both the NS ..pi.. bond and ..pi..* orbitals. The nitrogen 1s binding energy for the NS complex is almost 2 eV lower than that for the NO complex, suggesting a much more negative charge on the NS nitrogen. In contrast, the chromium, carbon, and oxygen core binding energies do not differ significantly between the two complexes. A formal potential model analysis of the (Cr-N-O) and (Cr-N-S) XPS shifts indicates a slightly more positive metal in the NS complex. These results are in agreement with Fenske-Hall approximate calculations and with other physical properties of the two compounds. 25 references, 10 figures, 4 tables.
- Research Organization:
- Univ. of Arizona, Tucson
- DOE Contract Number:
- AC02-80ER10746
- OSTI ID:
- 6036433
- Journal Information:
- Inorg. Chem.; (United States), Vol. 24:23
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBONYLS
BINDING ENERGY
CHROMIUM COMPLEXES
CYCLOPENTADIENE
NITROSO COMPOUNDS
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
GASES
HELIUM
KINETIC ENERGY
PHOTOELECTRON SPECTROSCOPY
ULTRAVIOLET RADIATION
VALENCE
X RADIATION
ALKENES
COMPLEXES
CYCLOALKENES
DATA
DIENES
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
FLUIDS
HYDROCARBONS
INFORMATION
IONIZING RADIATIONS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
POLYENES
RADIATIONS
RARE GASES
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)