Synthesis and Characterization of Low-Coordinate Divalent Aryl Transition-Metal Halide Analogues of Grignard Reagents: Precursors for Reduction to Metal-Metal-Bonded Complexes
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- 作者：Andrew D. Sutton ; Tailuan Ngyuen ; James C. Fettinger ; Marilyn M. Olmstead ; Gary J. Long ; Philip P. Power
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：June 11, 2007
- 年：2007
- 卷：46
- 期：12
- 页码：4809 - 4814
- 全文大小：109K
- 年卷期：v.46,no.12(June 11, 2007)
- ISSN：1520-510X
文摘
The synthesis and characterization of the series of divalent first-row aryl transition-metal(II) halide compounds[Cr(
-Cl)Ar']2 (1) and (Li(OEt2)Ar'MI2]2 (M = Mn (2), Fe (3), and Co (4); Ar' = C6H3-2,6-(C6H3-2,6-iPr2)2) aredescribed. 1-4 were prepared by the addition of one equiv of Ar'Li to the respective transition-metal dihalides.They were characterized by UV-vis spectroscopy, magnetic measurements, and by X-ray crystallography. In dimeric1, each chromium center has quasi-four-coordinate, square-planar geometry, in which the metal is terminally boundto a terphenyl ligand through the ipso carbon of the central ring and to two bridging chloride ligands. There is afurther interaction between chromium and an ipso carbon from one of the flanking -C6H3-2,6iPr2 rings. In contrast,for the iodo derivatives 2-4, LiI is not eliminated upon addition of LiAr' to MI2. Instead, the diethyl ether solvatedadducts, [Li(OEt2)Ar'MI2]2 (M = Mn (2), Fe (3), or Co (4)) were isolated. These possess a distorted cubane Li2M2I4core, in which the lithiums are bound to an ether and the transition metals are bound to a terphenyl group. Magneticmeasurements between 2 and 300 K reveal the expected weak antiferromagnetic exchange coupling in each ofthe complexes.
-Cl)Ar']2 (1) and (Li(OEt2)Ar'MI2]2 (M = Mn (2), Fe (3), and Co (4); Ar' = C6H3-2,6-(C6H3-2,6-iPr2)2) aredescribed. 1-4 were prepared by the addition of one equiv of Ar'Li to the respective transition-metal dihalides.They were characterized by UV-vis spectroscopy, magnetic measurements, and by X-ray crystallography. In dimeric1, each chromium center has quasi-four-coordinate, square-planar geometry, in which the metal is terminally boundto a terphenyl ligand through the ipso carbon of the central ring and to two bridging chloride ligands. There is afurther interaction between chromium and an ipso carbon from one of the flanking -C6H3-2,6iPr2 rings. In contrast,for the iodo derivatives 2-4, LiI is not eliminated upon addition of LiAr' to MI2. Instead, the diethyl ether solvatedadducts, [Li(OEt2)Ar'MI2]2 (M = Mn (2), Fe (3), or Co (4)) were isolated. These possess a distorted cubane Li2M2I4core, in which the lithiums are bound to an ether and the transition metals are bound to a terphenyl group. Magneticmeasurements between 2 and 300 K reveal the expected weak antiferromagnetic exchange coupling in each ofthe complexes.