Bonding in tris(. eta. sup 5 -cyclopentadienyl) actinide complexes. 3. Interaction of. pi. -neutral,. pi. -acidic, and. pi. -basic ligands with (. eta. sup 5 -C sub 5 H sub 5 ) sub 3 U sup 1

Journal Article · Wed Apr 12 00:00:00 EDT 1989 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00190a003· OSTI ID:5238240

Bursten, B E; Rhodes, L F; Strittmater, ^[1]

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1. Ohio State Univ., Columbus (USA)

A qualitative treatment of the bonding in Cp{sub 3}M (Cp = {eta}{sup 5}-C{sub 5}H{sub 5}) compounds under C{sub 3{upsilon}} symmetry reveals that the Cp{sub 3}{sup 3{minus}} ligand field contains a high-lying a{sub 2} orbital which is restricted by symmetry to interact only with metals that contain f orbitals. Quantitative investigation of the electronic structure of 5f{sup 3} Cp{sub 3}U via X{alpha}-SW molecular orbital calculations with quasi-relativistic corrections reveals that the Cp ligands donate electron density primarily into the U 6d orbitals while the three principally metal-based valence electrons are housed in the 5f orbitals. Electronic structure calculations of Cl{sub 3}U show that although Cl can be considered isolobal with Cp, it is a poorer donor ligand. Calculations of Cp{sub 3}U bonded to a fourth ligand L (L = H, CO, NO, OH) indicate that the {sigma}-bonding framework is essentially the same for {pi}-neutral (H), {pi}-acidic (CO, NO), or {pi}-basic (OH) ligands: Electron density is donated from the {sigma} orbital of the fourth ligand into a uranium orbital that is primarily 6d{sub z{sup 2}} in character with minor contributions from the 5f{sub z{sup 3}} orbital, the 7p{sub z} orbital, and the 7s orbital. In the {pi}-bonding framework, the U 5f orbitals are responsible for back-donation into the {pi}* orbitals of CO an NO, while acceptance of electron density from the {pi} orbitals of OH involves the U 6d orbitals and, to a lesser extent, the U 5f orbitals. The bonding scheme of Cp{sub 3}UNO suggests that this molecule may prove to be a rather unusual example of a linear NO{sup {minus}} ligand.

• DOE Contract Number: FG02-86ER13529
• OSTI ID: 5238240
• Journal Information: Journal of the American Chemical Society; (USA), Vol. 111:8; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
DIENES
ELECTRONIC STRUCTURE
ORGANOMETALLIC COMPOUNDS
URANIUM COMPLEXES
CHEMICAL BONDS
LIGANDS
MATHEMATICAL MODELS
MOLECULAR ORBITAL METHOD
PH VALUE
SYMMETRY
SYMMETRY GROUPS
THEORETICAL DATA
ACTINIDE COMPLEXES
COMPLEXES
DATA
HYDROCARBONS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
POLYENES
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials