Electronic Structure of the Hydroxo and Methoxo Oxometalate Anions MO3(OH)- and MO3(OCH3)- (M=Cr, Mo, and W)

Journal Article · Thu Dec 29 04:00:00 EST 2005 · Journal of Physical Chemistry A, 109(51):11771-11780

DOI:https://doi.org/10.1021/jp054666x· OSTI ID:877005

Waters, Tom; Wang, Xue B; Li, Shenggang; Kiran, Boggavarapu; Dixon, David A; Wang, Lai S

The electronic structure of the mononuclear hydroxo MO3(OH)- and methoxo MO3(OCH3)- Group 6 oxometalate anions (M ) Cr, Mo, and W) were examined by photodetachment photoelectron spectroscopy and electronic structure calculations at the density functional and CCSD(T) levels of theory. All of the anions exhibited high electron binding energies (>4.9 eV), with the lowest-energy detachment features arising from oxygen 2p-based orbitals. The combined experimental and theoretical results allowed the change in molecular orbital energy levels to be investigated as a function of metal (Cr, Mo, or W) and ligand (-OH, -OCH3). A number of fundamental thermodynamic properties of the anions and corresponding neutrals were predicted on the basis of the theoretical calculations. The calculations indicate high O-H bond dissociation energies for MO2(OR)(O-H) (R ) H, CH3) and MO3(O-H), consistent with their high Brønsted acidities (just below that of H2SO4 in the gas phase) and the high ionization energies of their conjugate base anions. This suggests that the corresponding radicals should readily abstract H atoms from organic molecules.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 877005
• Report Number(s): PNNL-SA-48098; 3565; 3568; KC0301020
• Journal Information: Journal of Physical Chemistry A, 109(51):11771-11780, Journal Name: Journal of Physical Chemistry A, 109(51):11771-11780 Journal Issue: 51 Vol. 109; ISSN 1089-5639; ISSN JPCAFH
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CHROMIUM COMPLEXES
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
ENERGY LEVELS
Environmental Molecular Sciences Laboratory
MOLYBDENUM COMPLEXES
PHOTOELECTRON SPECTROSCOPY
THERMODYNAMIC PROPERTIES
TUNGSTEN COMPLEXES