Synthesis of Mixed Alkali-Metal-Zinc Enolate Complexes Derived from 2,4,6-Trimethylacetophenone: New Inverse Crown Structures

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• 作者：Sharon E. Baillie ; Eva Hevia ; Alan R. Kennedy ; Robert E. Mulvey
• 刊名：Organometallics
• 出版年：2007
• 出版时间：January 1, 2007
• 年：2007
• 卷：26
• 期：1
• 页码：204 - 209
• 全文大小：119K
• 年卷期：v.26,no.1(January 1, 2007)
• ISSN：1520-6041

文摘

The solution and solid-state characterization of two new mixed alkali-metal-zinc enolate compoundsis reported. These compounds are prepared by reaction of the relevant mixed-metal base [MZn(HMDS)₃](M = Na, K; HMDS = 1,1,1,3,3,3-hexamethyldisilazide) with a stoichiometric amount of the stericallydemanding ketone 2,4,6-trimethylacetophenone. Thus, the new mixed-metal enolate compounds [Na₂Zn₂{OC(=CH₂)Mes}₆{OC(CH₃)Mes}₂] (2) and [K₂Zn₂{OC(=CH₂)Mes}₆(CH₃Ph)₂] (3) are obtained forM = Na, K, respectively. X-ray crystallographic studies reveal that both compounds adopt the samestructural motif, which define them as inverse crown complexes, a cationic eight-membered [(MOZnO)₂]²⁺ring which hosts in its core two additional enolate ligands. Each Zn center is bonded to four anionicenolate ligands framing the structure, whereas the alkali metals form much weaker interactions with theoxygen atoms and complete their coodination sphere by bonding to a neutral molecule, an unenolisedketone for M = Na or toluene for M = K.