Molecular Zinc Species with Ge–Zn and Sn–Zn Bonds: A Reversible Insertion of a Stannylene into a Zinc–Carbon Bond

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• 作者：Jeremy D. Erickson ; Ryan D. Riparetti ; James C. Fettinger ; Philip P. Power
• 刊名：Organometallics
• 出版年：2016
• 出版时间：June 27, 2016
• 年：2016
• 卷：35
• 期：12
• 页码：2124-2128
• 全文大小：344K
• 年卷期：0
• ISSN：1520-6041

文摘

The tetrylenes Ge(Ar^Me₆)₂ and Sn(Ar^Me₆)₂ (Ar^Me₆ = C₆H₃-2,6-(C₆H₂-2,4,6-(CH₃)₃)₂) reacted with dimethylzinc to afford the insertion products (Ar^Me₆)₂Ge(Me)ZnMe (1) and (Ar^Me₆)₂Sn(Me)ZnMe (3), which feature Ge–Zn and Sn–Zn bonds as well as two-coordinate zinc atoms. Crystals of 1 were found to be unsuitable for X-ray crystallography, so the ethyl-substituted (Ar^Me₆)₂Ge(Et)ZnEt (2) was synthesized in a parallel way to provide crystals suitable for X-ray studies. These showed the structure to be similar to that of 3. The reaction of Pb(Ar^Me₆)₂ with dimethylzinc yielded Ar^Me₆ZnMe with a linearly coordinated zinc atom via ligand exchange but no characterizable, new lead product was obtained. The reaction of Sn(Ar^Me₆)₂ with dimethylzinc is reversible in hydrocarbon solution at room temperature and displayed a dissociation constant K_diss and a ΔG_diss of 0.0028(5) and 14(4) kJ mol^–1 at 298 K, respectively. Compounds 1–4 were characterized by NMR and IR spectroscopy as well as by X-ray crystallography for 1, 3, and 4.