Steric Enhancement of Group 12 Metal Hydride Stability and the Reaction of an Arylzinc Hydride with Tetramethylpiperidinyl Oxide (TEMPO)

详细信息    查看全文

• 作者：Zhongliang Zhu ; James C. Fettinger ; Marilyn M. Olmstead ; Philip P. Power*
• 刊名：Organometallics
• 出版年：2009
• 出版时间：April 13, 2009
• 年：2009
• 卷：28
• 期：7
• 页码：2091-2095
• 全文大小：147K
• 年卷期：v.28,no.7(April 13, 2009)
• ISSN：1520-6041

文摘

The synthesis and characterization of arylzinc hydrides Ar*Zn(μ-H)₂ZnAr* (Ar* = C₆H₃-2,6-(C₆H₂-2,4,6-Prⁱ₃)₂, 5) and {(4-Me₃Si-Ar*)Zn(μ-H)₂Zn(Ar*-4-SiMe₃)} (4-Me₃Si-Ar* = C₆H₂-2,6-(C₆H₂-2,4,6-Prⁱ₃)₂-4-SiMe₃, 7) as well as the monomeric arylcadmium hydride Ar*CdH (9) are described. They were prepared by the transmetalation of the corresponding aryl metal iodides with NaH. The Ar*CdH monomer displayed significantly greater thermal stability than its recently reported dimeric congener Ar′Cd(μ-H)₂CdAr′ (Ar′ = C₆H₃-2,6-(C₆H₃-2,6-Prⁱ₂)₂), which decomposed at room temperature to afford Ar′CdCdAr′. This result supports the proposal that decomposition of the metal hydrides occurs by an associative mechanism. The reactions of these compounds with TEMPO (2,2,6,6-tetramethylpiperidinyl oxide) were also examined, but the only crystalline product obtained was 4-Me₃Si-Ar*ZnTEMPO, in which the metal is bound to the TEMPO ligand in a quasi side-on fashion primarily through the oxygen but with a significant zinc−nitrogen interaction.