Synthesis of mixed alkali-metal-zinc enolate complexes derived from 2,4,6-trimethylacetophenone: New inverse crown structures
Synthesis of mixed alkali-metal-zinc enolate complexes derived from 2,4,6-trimethylacetophenone: New inverse crown structures
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DOI：
10.1021/om060878k
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发表时间：
2007-01-01
期刊：
影响因子：
2.8
通讯作者：
Mulvey, Robert E.
中科院分区：
文献类型：
--
作者：
Baillie, Sharon E.;Hevia, Eva;Mulvey, Robert E.
报道了两种新的碱金属锌烯醇盐混合化合物的溶液和固态表征。这些化合物是通过相关的混合金属碱[MZn（HMDS）（3）]（M = Na、K; HMDS = 1，1，1，3，3，3-六甲基二硅基氨基化物）与化学计量量的要求空间位阻的酮2，4，6-三甲基苯乙酮反应制备的。在M = Na，K时，得到了新的混合金属烯醇化物[Na_2 Zn_2 {OC（CH_2）Mes}（6）{OC（CH_3）Mes}（2）]（2）和[K_2 Zn_2 {OC（CH_2）Mes}（6）（CH_3 Ph）（2）]（3）. X-射线晶体学研究表明，两种化合物具有相同的结构基序，它们被定义为反冠醚配合物，一个阳离子八元[（MOZnO）（2）]（2+）环，在其核心有两个额外的烯醇化配体。每个Zn中心与四个阴离子烯醇化物配体键合，形成结构，而碱金属与氧原子形成弱得多的相互作用，并通过与中性分子键合来完成其配位球，对于M = Na，为未烯醇化的酮，对于M = K，为甲苯。
The solution and solid-state characterization of two new mixed alkali-metal-zinc enolate compounds is 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 sterically demanding 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 for M = Na, K, respectively. X-ray crystallographic studies reveal that both compounds adopt the same structural 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 anionic enolate ligands framing the structure, whereas the alkali metals form much weaker interactions with the oxygen atoms and complete their coodination sphere by bonding to a neutral molecule, an unenolised ketone for M = Na or toluene for M = K.