Synthesis and Characterization of the Homologous M-M Bonded Series Ar'MMAr' (M = Zn, Cd, or Hg; Ar' = C6H3-2,6-(C6H3-2,6-Pri
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- 作者：Zhongliang Zhu ; Marcin Brynda ; Robert J. Wright ; Roland C. Fischer ; W. Alexander Merrill ; Eric Rivard ; Robert Wolf ; James C. Fettinger ; Marilyn M. Olmstead ; Philip P. Power
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：September 5, 2007
- 年：2007
- 卷：129
- 期：35
- 页码：10847 - 10857
- 全文大小：474K
- 年卷期：v.129,no.35(September 5, 2007)
- ISSN：1520-5126
文摘
The synthesis and structural characterization of the first homologous, molecular M-M bondedseries for the group 12 metals are reported. The compounds Ar'MMAr' (M = Zn, Cd, or Hg; Ar' = C6H3-2,6-(C6H3-2,6-Pri2)2) were synthesized by reduction of the corresponding arylmetal halides by alkali metal/graphite (Zn or Hg) or sodium hydride (Cd). These compounds possess almost linear C-M-M-C corestructures with two-coordinate metals. The observed M-M bonds distances were 2.3591(9), 2.6257(5),and 2.5738(3) Å for the zinc, cadmium, and mercury species, respectively. The shorter Hg-Hg bond incomparison to that of Cd-Cd is consistent with DFT calculations which show that the strength of the Hg-Hg bond is greater. The arylmetal halides precursors (Ar'MI)1 or 2, and the highly reactive hydrides (Ar'MH)1 or 2,were also synthesized and fully characterized by X-ray crystallography (Zn and Cd) and multinuclear NMRspectroscopy. The arylzinc and arylcadmium iodides have iodide-bridged dimeric structures, whereas thearylmercury iodide, Ar'HgI, is monomeric. The arylzinc and arylcadmium hydrides have symmetric (Zn) orunsymmetric (Cd) 
-H-bridged structures. The Ar'HgH species was synthesized and characterized byspectroscopy, but a satisfactory refinement of the structure was precluded by the contamination of monomericAr'HgH by Ar'H. It was also shown that the decomposition of Ar'Cd(-H)2CdAr' at room temperature leadsto the M-M bonded Ar'CdCdAr', thereby supporting the view that the reduction of the iodide proceeds viathe hydride intermediate.
-H-bridged structures. The Ar'HgH species was synthesized and characterized byspectroscopy, but a satisfactory refinement of the structure was precluded by the contamination of monomericAr'HgH by Ar'H. It was also shown that the decomposition of Ar'Cd(-H)2CdAr' at room temperature leadsto the M-M bonded Ar'CdCdAr', thereby supporting the view that the reduction of the iodide proceeds viathe hydride intermediate.