A comparative fully relativistic/nonrelativistic first-principles X[alpha]-DVM and photoelectron spectroscopic investigation of electronic structure in homologous 4f and 5f tris([eta][sup 5]-cyclopentadienyl)metal(IV) alkoxide complexes

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00070a018· OSTI ID:6767844

Gulino, A; Di Bella, S; Fragala, I ^[1]; Casarin, M ^[2]; Seyam, A M; Marks, T J ^[3]

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1. Universita di Catania (Italy)
2. Universita di Padova (Italy)
3. Northwestern Univ., Evanston, IL (United States)

The electronic structure of ([eta][sup 5]-C[sub 5]H[sub 5])[sub 3]MOR (M = Ce, Th, U) complexes has been investigated by He I and He II UV photoelectron spectroscopy combined with SCF X[alpha]-DVM calculations. Fully relativistic Dirac-Slater calculations were also carried out for the M = Th complex. The nonrelativistic calculations indicate that metal-ligand interactions involving the highest energy ligand orbitals involve primarily metal 5f orbitals while 6d admixtures are found for lower energy orbitals. The M-O bonding is both [sigma] and [pi] in nature and involves primarily metal 6d atomic orbitals. Evidence of a charge redistribution mechanism along the CH[sub 3][yields]O[yields]M[yields]Cp[sub 3] direction provides a satisfactory explanation for the shortened M-O distances and strong propensity for nearly linear M-O-CH[sub 3] linkages observed in diffraction studies. The fully relativistic calculations show that metal d contributions are slightly underestimated at the nonrelativistic level. Such deviations do not, however, alter the overall description of the metal-ligand bonding. The nonrelativistic configuration of the metal center compares well with the relativistic data. Gas-phase ionization energies can be accurately and comparably evaluated at the computationally more efficient nonrelativistic level if optimized basis sets and potential representations are used.

• OSTI ID: 6767844
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 32:18; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400700* -- Radiochemistry & Nuclear Chemistry
ACTINIDE COMPLEXES
CALCULATION METHODS
CERIUM COMPLEXES
COMPLEXES
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
MATHEMATICAL MODELS
MOLECULAR ORBITAL METHOD
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
RARE EARTH COMPLEXES
SPECTROSCOPY
THORIUM COMPLEXES
URANIUM COMPLEXES