Mono(pentamethylcyclopentadienyl)uranium(III) Complexes: Synthesis, Properties, and X-ray Structures of (-C5Me5)
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- 作者：Larry R. Avens ; Carol J. Burns ; Raymond J. Butcher ; David L. Clark ; John C. Gordon ; Ann R. Schake ; Brian L. Scott ; John G. Watkin ; and Bill D. Zwick
- 刊名：Organometallics
- 出版年：2000
- 出版时间：February 21, 2000
- 年：2000
- 卷：19
- 期：4
- 页码：451 - 457
- 全文大小：99K
- 年卷期：v.19,no.4(February 21, 2000)
- ISSN：1520-6041
文摘
The uranium(III) iodide complex UI3(THF)4 reacts cleanly at ambient temperature with1 equiv of sodium and potassium pentamethylcyclopentadienide salts in tetrahydrofuran toform the mono-ring uranium(III) complex (
-C5Me5)UI2(THF)3 (1). Additionally, reaction ofUI3(THF)4 with 2 equiv or more of K(C5Me5) in THF solution leads to the formation of thebis-ring adduct (-C5Me5)2UI(THF) (2) in high yield. In the solid state 1 exhibits a pseudo-octahedral mer,trans ligand geometry with the C5Me5 ligand occupying one axial position.U-I bond lengths range from 3.161(1) to 3.179(1) Å, while U-O distances to the THF ligandslie in the range 2.496(8)-2.594(10) Å. 1 also provides a convenient entry into a variety ofother mono-ring complexes of uranium(III). In the presence of excess pyridine, the coordinatedTHF ligands of 1 are readily displaced to form the tris(pyridine) adduct (-C5Me5)UI2(py)3(3), which exhibits a mer,trans ligand geometry in the solid state similar to that of 1.Metathesis of the iodide ligands in 1 with 2 equiv of KN(SiMe3)2 affords the bis(amido)complex (-C5Me5)U[N(SiMe3)2]2 (4). An X-ray diffraction study of this molecule reveals thatmethyl groups from both amido ligands are involved in agostic interactions with the uranium(III) center.
-C5Me5)UI2(THF)3 (1). Additionally, reaction ofUI3(THF)4 with 2 equiv or more of K(C5Me5) in THF solution leads to the formation of thebis-ring adduct (-C5Me5)2UI(THF) (2) in high yield. In the solid state 1 exhibits a pseudo-octahedral mer,trans ligand geometry with the C5Me5 ligand occupying one axial position.U-I bond lengths range from 3.161(1) to 3.179(1) Å, while U-O distances to the THF ligandslie in the range 2.496(8)-2.594(10) Å. 1 also provides a convenient entry into a variety ofother mono-ring complexes of uranium(III). In the presence of excess pyridine, the coordinatedTHF ligands of 1 are readily displaced to form the tris(pyridine) adduct (-C5Me5)UI2(py)3(3), which exhibits a mer,trans ligand geometry in the solid state similar to that of 1.Metathesis of the iodide ligands in 1 with 2 equiv of KN(SiMe3)2 affords the bis(amido)complex (-C5Me5)U[N(SiMe3)2]2 (4). An X-ray diffraction study of this molecule reveals thatmethyl groups from both amido ligands are involved in agostic interactions with the uranium(III) center.